PE23.1-21 | Gastrointestinal and Hepatobiliary System — Glossary

Pale, clay-coloured, or grey stools resulting from absence of bile pigments due to biliary obstruction or severe cholestasis; a cardinal sign of extrahepatic biliary atresia or complete bile duct obstruction.

Acute onset diarrhoea (≥3 loose/watery stools per 24 hours) with or without vomiting, lasting less than 14 days; most commonly caused by viral pathogens (rotavirus, norovirus) in young children.

An acute inflammatory condition of the liver characterised by hepatocellular injury, elevated transaminases (ALT/AST), and often jaundice, lasting less than 6 months; may be viral, drug-induced, autoimmune, or metabolic in origin.

A medical emergency defined as hepatic encephalopathy plus coagulopathy (INR >1.5) occurring within 8 weeks of onset of acute liver disease in a child with no prior known liver disease; requires PICU and liver transplant centre management.

Absence of ganglion cells in the enteric nervous system plexuses of the bowel wall; the hallmark of Hirschsprung's disease; confirmed on suction rectal biopsy.

Autosomal dominant disorder (JAG1/NOTCH2 mutation) characterised by bile duct paucity causing cholestatic CLD, plus cardiovascular anomalies, butterfly vertebrae, posterior embryotoxon, and characteristic facies.

Enzyme elevated in cholestatic and infiltrative liver disease; paradoxically LOW in Wilson disease FHF due to copper inhibition — a key diagnostic clue.

Autosomal recessive disorder (PiZZ genotype) in which misfolded A1AT protein accumulates in hepatocytes, causing ER stress and progressive liver disease; lung disease results separately from absent protease inhibitory function.

A liver-specific enzyme found primarily in hepatocytes; elevated levels (especially >10× ULN) indicate hepatocellular injury; more liver-specific than AST.

Clinical scoring system for risk-stratification of appendicitis in children; maximum 10 points; score ≥7 = high probability (surgical referral); 5-6 = equivocal (observe + USG); <4 = low probability (discharge).

Dysentery caused by Entamoeba histolytica; typically more insidious onset, lower fever, few pus cells on stool microscopy, and trophozoites containing RBCs on fresh stool examination.

A highly specific (near 100%) IgA antibody against endomysium (connective tissue around smooth muscle); used as a second-line confirmatory serological test for coeliac disease.

Antibody to Hepatitis B surface antigen; indicates protective immunity against HBV from either past resolved infection or successful vaccination; anti-HBs ≥10 IU/L = seroprotection.

Protective antibody against HBV surface antigen; positive = immune to HBV from either past infection (anti-HBc also positive) or vaccination (anti-HBc negative).

The first-line serological test for coeliac disease with high sensitivity (>95%) and specificity; must be interpreted alongside total serum IgA because IgA-deficient patients will have a false-negative result.

Rhythmic involuntary flapping of the dorsiflex wrist ('liver flap') caused by lapses in postural tone; a sign of Grade I–II hepatic encephalopathy, absent in deeper grades.

Immune-mediated hepatitis characterised by autoantibodies (ANA/anti-SMA in Type 1; anti-LKM1 in Type 2), elevated IgG, and interface hepatitis on biopsy; treated with corticosteroids and azathioprine.

Dysentery caused by bacterial invasion of the colonic mucosa, most commonly by Shigella; characterised by fever, numerous pus cells on stool microscopy, and positive stool culture.

Progressive inflammatory fibro-obliteration of the extrahepatic biliary tree presenting in neonates as conjugated jaundice with acholic stools; treated by Kasai portoenterostomy ideally before 60 days of age.

Green or yellow-green vomiting indicating that bile-stained duodenal contents are being expelled; implies an obstruction at or distal to the duodenojejunal flexure and is a surgical emergency in neonates and infants.

Presence of conjugated (direct) bilirubin in the urine, causing dark 'cola-coloured' urine; a sign of hepatocellular or obstructive jaundice; unconjugated (indirect) bilirubin is not excreted in urine as it is protein-bound.

White, foamy, triangular lesions on the conjunctiva (temporal side) consisting of desquamated epithelial cells and bacteria; pathognomonic of Vitamin A deficiency from fat malabsorption in chronic cholestasis.

A 7-type visual classification of stool consistency (1 = hard lumps; 7 = liquid); types 3-4 are ideal; types 1-2 indicate constipation; types 5-7 indicate diarrhoea; useful for stool diary and monitoring laxative therapy.

Post-hepatic portal hypertension from obstruction of the hepatic veins or inferior vena cava; presents with painful hepatomegaly, ascites, and liver failure; associated with hypercoagulable states.

Dilated, tortuous periumbilical superficial veins visible on the abdominal wall in portal hypertension; blood flows away from the umbilicus through recanalized paraumbilical veins as a portosystemic collateral.

Replacement of the thrombosed portal vein by a tangle of tortuous collateral vessels at the hepatic hilum, visible on Doppler USG; pathognomonic of chronic EHPVO.

A third-generation cephalosporin antibiotic used parenterally for severe or complicated Shigella dysentery at 50–100 mg/kg/day IV/IM once daily.

Endoscopic biopsy of the distal duodenum (at least 4 samples including duodenal bulb) demonstrating villous atrophy, crypt hyperplasia, and increased intraepithelial lymphocytes; the gold standard for diagnosing coeliac disease.

Copper-carrying glycoprotein synthesised in the liver; low serum ceruloplasmin (<20 mg/dL) is a key diagnostic marker for Wilson disease.

Cystic fibrosis transmembrane conductance regulator gene; mutations (most commonly F508del in most populations) impair chloride channel function in epithelial cells, causing the multisystem phenotype of cystic fibrosis.

Region in the area postrema of the medulla oblongata, outside the blood-brain barrier, that detects blood-borne emetic stimuli (drugs, toxins, metabolites) and relays signals to the vomiting centre.

Severe watery diarrhoea caused by Vibrio cholerae; cholera toxin activates adenylate cyclase → massively increased cAMP → CFTR-mediated chloride secretion → rice-water stools; treated with ORS + single-dose azithromycin/doxycycline.

Liver function test pattern characterised by markedly elevated ALP and GGT with relatively modest ALT/AST elevation; indicates impaired bile flow from biliary obstruction or ductular disease.

Any liver disease persisting more than 6 months, causing progressive hepatic fibrosis and eventually cirrhosis with its complications of portal hypertension and hepatic insufficiency.

A fluoroquinolone antibiotic used as first-line treatment for Shigella dysentery in India at 15 mg/kg/day in two divided doses for 3 days; note: contraindicated in EHEC infection.

Irreversible end-stage of hepatic fibrosis characterised by replacement of normal hepatic architecture with fibrous bands and regenerative nodules, causing portal hypertension and hepatic insufficiency.

Rapid urease biopsy test for H. pylori: gastric biopsy placed in urea-containing gel changes colour from yellow to pink/red if H. pylori urease is present; result within 1–24 hours.

An immune-mediated gluten-sensitive enteropathy in which dietary gluten (from wheat, rye, barley) triggers a T-cell-mediated response causing villous atrophy and malabsorption in genetically predisposed individuals (HLA-DQ2/DQ8).

A surgical emergency resulting from elevated pressure within a fascial compartment, compromising blood flow to muscles and nerves; can complicate IO access with large-volume extravasation; requires fasciotomy.

Elevated direct (conjugated, water-soluble) bilirubin >20% of total bilirubin; causes dark urine and pale stools; indicates hepatocellular disease or biliary obstruction (cholestasis).

Infrequent, difficult, or painful defecation; defined in children using ROME IV criteria (≤2 defecations/week plus one or more associated features for ≥1 month).

Dark red, mucus-mixed bloody stool seen in intussusception, resulting from mucosal ischaemia and sloughing of the intussuscepted bowel segment; a late sign indicating established obstruction and ischaemia.

Recurrent, stereotyped episodes of intense nausea and vomiting lasting hours to days, with complete well-being between episodes; associated with migraine family history; managed with acute antiemetics and prophylactic agents.

An autosomal recessive multisystem disease caused by CFTR gene mutations, leading to abnormally viscous mucus, progressive lung disease, and pancreatic exocrine insufficiency causing malabsorption.

A test of proximal small intestinal mucosal function; low urinary D-xylose excretion after an oral dose indicates mucosal malabsorption (e.g., coeliac disease), distinguishing it from pancreatic exocrine insufficiency where D-xylose absorption is normal.

Passage of three or more loose or watery stools in a 24-hour period; classified by duration (acute <14 days, persistent 14-29 days, chronic ≥30 days) and character (watery vs dysentery).

A luminal amoebicide used after metronidazole to eradicate intestinal cysts of Entamoeba histolytica and prevent relapse; given at 20 mg/kg/day in 3 divided doses for 10 days.

Targeted antiviral drugs for hepatitis C that inhibit specific viral enzymes (NS3/4A protease, NS5A, NS5B polymerase); sofosbuvir-based regimens achieve >95% sustained virological response (cure) in 8–12 weeks.

Active pharmacological or rectal removal of a fecal impaction; must be completed before starting maintenance laxative therapy; oral PEG at 1-1.5 g/kg/day for 3-6 days is preferred.

Radiological finding on plain abdominal X-ray showing distension of the stomach and proximal duodenum as two air bubbles with absence of distal gas; diagnostic of duodenal atresia in a neonate.

Diarrhoea characterised by blood and mucus in stool with tenesmus, indicating invasive bacterial (Shigella, Salmonella, EIEC) or parasitic (Entamoeba histolytica) infection; requires targeted antibiotic treatment.

E. coli serotype O157:H7 that does not invade the mucosa but produces Shiga toxin (verotoxin), causing bloody diarrhoea without fever; antibiotic use in this infection is absolutely contraindicated because it increases Shiga toxin release.

Thrombotic occlusion of the extrahepatic portal vein with cavernous transformation; the commonest cause of portal hypertension in Indian children; characterised by normal liver function.

Endoscopic application of elastic bands to oesophageal varices to cause strangulation and obliteration; preferred endoscopic technique for variceal haemorrhage treatment and prophylaxis.

A protozoan parasite transmitted via cyst ingestion; trophozoites invade the colonic mucosa forming flask-shaped ulcers, causing amoebic dysentery characterised by mucoid bloody stools with trophozoites that contain ingested red blood cells.

Umbilicus pushed outward by raised intraperitoneal pressure; a clinical sign of tense ascites.

Leakage of infused fluid or drug into the perivascular or periosseous soft tissues due to the cannula/needle tip being outside the vein or marrow cavity; presents as localised swelling and is a complication requiring immediate removal and site change.

A battery-powered drill device used for intraosseous access; allows rapid, reliable penetration of the tibial cortex with a specially designed needle; preferred over manual Jamshidi needle in paediatric emergencies.

Starter therapeutic milk formula used in the initial phase (days 1–7) of management of severe acute malnutrition, providing 75 kcal/100 mL; often administered via NG tube when the child lacks appetite.

The route of spread of enteric pathogens including Shigella and E. histolytica, via contaminated food, water, or hands; prevention relies on handwashing, safe water, and improved sanitation.

A large, hard mass of stool lodged in the rectum or colon that cannot be passed by normal defecation; requires active disimpaction before maintenance therapy.

A characteristic sweet-musty odour of the breath in severe hepatic failure, caused by exhaled mercaptans (dimethyl sulphide); a clinical sign of advanced hepatic encephalopathy.

The appearance of blood in the hub of the IV needle when the tip enters the vein lumen, confirming intravascular placement; the signal to lower the needle angle and advance the plastic cannula.

Palpatory sign of large-volume ascites: a transmitted vibratory impulse felt across the abdomen when one flank is flicked, with a helper's hand on the midline to prevent transmission through subcutaneous fat.

Blood component containing all coagulation factors used to treat active bleeding or before invasive procedures in FHF; NOT recommended for prophylactic INR correction.

Acute liver injury causing hepatic encephalopathy and coagulopathy (INR >1.5) within 8 weeks of illness onset, in the absence of pre-existing liver disease.

ROME IV-defined category of chronic abdominal pain in children: ≥4 episodes per month for ≥2 months, without structural or biochemical abnormality explaining the pain; managed with biopsychosocial approach.

Constipation with no identifiable organic cause, accounting for >90% of paediatric constipation; driven by withholding behaviour and a self-perpetuating pain-withholding cycle.

Pathological form of gastro-oesophageal reflux causing symptoms or complications (oesophagitis, poor weight gain, aspiration); distinguished from physiological regurgitation by severity and impact.

A protein complex found in wheat (gliadin component), rye, and barley; the dietary trigger of coeliac disease; absent in rice, maize, jowar, bajra, and quinoa.

The only effective treatment for coeliac disease; requires lifelong elimination of wheat (including atta, maida, sooji), rye, and barley; rice, maize, jowar, bajra, and quinoa are safe.

Life-threatening triad of microangiopathic haemolytic anaemia, thrombocytopenia, and acute kidney injury; most commonly caused by EHEC O157:H7 Shiga toxin; antibiotics are CONTRAINDICATED as they worsen toxin release.

Rapid bedside stool examination technique: fresh stool + normal saline on slide, covered and examined immediately under microscopy for motile organisms; Vibrio cholerae shows shooting-star darting motility of comma-shaped rods.

Marker of active viral replication; positive in acute HBV and active chronic HBV; associated with high infectivity and high HBV DNA levels; seroconversion to anti-HBe indicates viral replication control.

A serological marker indicating current Hepatitis B virus infection (acute or chronic); its persistent presence beyond 6 months defines chronic HBV infection.

Small-vessel IgA-mediated vasculitis causing palpable purpura (lower limbs/buttocks), abdominal pain (can precede rash), arthritis, and haematuria; abdominal pain is due to bowel wall oedema and haemorrhage.

A neuropsychiatric syndrome resulting from liver failure, caused primarily by ammonia accumulation; ranges from subtle behavioural changes and sleep-cycle reversal (Grade I) through confusion (Grade II) and stupor (Grade III) to coma (Grade IV).

A neuropsychiatric complication of liver failure caused by accumulation of ammonia and other toxins, manifesting as confusion, drowsiness, and ultimately coma; graded I–IV by the West Haven criteria.

Perisinusoidal cell in the liver that, when activated by injury signals (TGF-beta, PDGF), transforms into a myofibroblast-like cell producing collagen — the primary driver of hepatic fibrosis.

Difference between wedged and free hepatic venous pressures; the best haemodynamic measure of portal hypertension severity; HVPG >12 mmHg indicates risk of variceal haemorrhage.

An RNA virus transmitted by the faeco-oral route; the commonest cause of acute viral hepatitis in Indian children; causes self-limiting disease with no chronic sequelae; IgM anti-HAV is the diagnostic marker of acute infection.

An RNA virus transmitted by the faeco-oral route; causes self-limiting acute hepatitis in most individuals but is associated with fulminant hepatic failure and case-fatality rates of 20–25% in pregnant women in the third trimester.

Liver function test pattern with markedly elevated ALT and AST (>5× ULN) with relatively modest ALP/GGT elevation; indicates hepatocyte injury from viral, immune, toxic, or metabolic causes.

Liver palpable below the right costal margin in the midclavicular line; recorded in centimetres below the costal margin; normal in children under 3 years up to 2 cm; above 2 cm = hepatomegaly at any age.

Functional acute kidney injury occurring in severe liver disease, caused by renal vasoconstriction secondary to systemic and splanchnic vasodilation; renal histology is normal and the condition is reversible with liver transplant.

Congenital absence of ganglion cells in the myenteric (Auerbach's) and submucosal (Meissner's) plexuses of the distal colon/rectum, causing functional obstruction; presents with delayed meconium passage (>48 h) and abdominal distension; diagnosed by rectal biopsy showing aganglionosis.

The most serious complication of Hirschsprung's disease — bacterial overgrowth and intestinal wall invasion causing toxic megacolon, fever, explosive bloody diarrhoea, and septic shock; a medical/surgical emergency.

The standard formula for calculating daily maintenance fluid requirements in children: 100 mL/kg for the first 10 kg + 50 mL/kg for the next 10 kg + 20 mL/kg for each additional kg above 20 kg.

Elevated blood ammonia (>80 µmol/L in children) resulting from impaired hepatic urea cycle in FHF; drives astrocyte swelling and cerebral oedema — the principal cause of death in FHF.

Pancytopenia (thrombocytopenia, anaemia, leucopenia) resulting from splenic sequestration of blood cells in congestive splenomegaly; bone marrow is normal and reactive.

Hypertrophy of the pyloric muscle causing progressive gastric outlet obstruction in infants aged 2–8 weeks; presents with projectile non-bilious vomiting, metabolic alkalosis, and an olive-shaped abdominal mass; diagnosed by USG, treated by Ramstedt's pyloromyotomy.

The serological marker of acute Hepatitis A infection; detectable from symptom onset and persists for 3–6 months; IgG anti-HAV indicates past infection or successful vaccination (protective immunity).

Antibody to Hepatitis B core antigen, IgM class; indicates acute HBV infection; becomes IgG anti-HBc in chronic infection; useful in distinguishing acute from chronic HBV.

WHO/UNICEF clinical assessment framework classifying dehydration as None, Some, or Severe based on four signs: consciousness/activity, eye appearance, drinking behaviour, and skin pinch; determines ORS Plan (A/B/C).

Leakage of non-vesicant IV fluid into surrounding tissue; the most common complication of peripheral IV cannulation in children; recognised by swelling, pallor, and slowing of the infusion rate.

Standardised measure of prothrombin time; INR >1.5 is required (along with HE) to define FHF; INR >4 is a poor prognostic marker and an indication for liver transplant listing.

T lymphocytes located within the intestinal epithelial layer; normally <20–25 per 100 enterocytes; elevated IELs (>30–40 per 100 enterocytes) are the earliest histological change in coeliac disease (Marsh 1).

Emergency vascular access achieved by inserting a needle through the cortex of a long bone into the medullary cavity, which communicates with the venous circulation; indicated when peripheral IV access fails in a critical emergency.

Telescoping of a proximal segment of bowel (usually ileum) into a distal segment (usually caecum), causing obstruction and ischaemia; peak age 6–18 months; treated with pneumatic/hydrostatic enema reduction.

The insertion of a short plastic cannula into a peripheral vein to provide intravenous access for fluid therapy, medications, or blood products; in children, preferred sites include the dorsum of hand, antecubital fossa, and saphenous vein.

Surgical hepatoportoenterostomy in which a Roux-en-Y jejunal loop is anastomosed to the liver hilum to restore bile drainage in biliary atresia; success rate >80% when performed before 60 days of age.

Golden-brown rings at the corneal periphery (Descemet's membrane) caused by copper deposition; pathognomonic of Wilson disease with neurological involvement, but may be absent in acute FHF presentation.

Osmotic laxative (non-absorbable disaccharide) that draws water into the colon; second-line alternative to PEG, especially in infants; dose 1–2 mL/kg twice daily; side effect is bloating and flatulence.

Non-invasive ultrasound-based technique measuring liver stiffness (in kPa) as a surrogate for fibrosis stage; used to monitor fibrosis progression and response to treatment without repeated liver biopsy.

Surgical replacement of a diseased liver with a donor organ; the only definitive treatment for FHF that does not respond to medical management; also curative for Wilson disease (corrects the metabolic defect).

Opioid receptor agonist antimotility antidiarrhoeal; CONTRAINDICATED in children under 2 years (risk of paralytic ileus, toxic megacolon, respiratory depression, and death); not recommended for routine paediatric AGE.

Impaired absorption of one or more nutrients from the gastrointestinal tract, resulting in nutritional deficiencies, growth failure, and abnormal stool characteristics such as steatorrhoea.

Abnormal rotation and fixation of the intestine during fetal development, predisposing to midgut volvulus — a surgical emergency presenting with bilious vomiting in neonates.

A histological grading system for duodenal biopsy changes in coeliac disease: Marsh 0 = normal; Marsh 1 = increased intraepithelial lymphocytes; Marsh 2 = crypt hyperplasia + IELs, normal villi; Marsh 3 = villous atrophy (3a partial, 3b subtotal, 3c total); Marsh 4 = hypoplastic atrophy.

Surface landmark for the appendix: one-third of the way from the right anterior superior iliac spine to the umbilicus; maximum tenderness at this point in appendicitis.

Remnant of the omphalomesenteric duct; rule of 2s: 2% population, 2 feet from ileocaecal valve, 2 inches long, presents within first 2 years; contains ectopic gastric or pancreatic tissue causing painless rectal bleeding or obstruction.

Chronic dilatation and hyposensitivity of the rectum resulting from long-standing functional constipation; the distended rectum no longer generates normal defecation urge, perpetuating the cycle.

Reactive enlargement of mesenteric lymph nodes, typically following upper respiratory tract infection; mimics appendicitis clinically; diagnosed by ultrasound showing enlarged nodes with a normal appendix; managed conservatively.

Acid-base disturbance characterised by elevated plasma bicarbonate and pH, resulting from prolonged loss of HCl (as in HPS vomiting) or excessive alkali intake; compensated by hypoventilation.

A nitroimidazole antibiotic and the drug of choice for amoebic dysentery (30–40 mg/kg/day in 3 divided doses for 7–10 days); kills tissue trophozoites but ineffective against luminal cysts.

Mechanical haemolysis caused by red blood cells fragmenting as they pass through fibrin strands in damaged small vessels; identified on peripheral blood smear as schistocytes; a key component of HUS.

Twisting of the intestines around the superior mesenteric artery axis, a catastrophic complication of malrotation causing ischaemia of the entire midgut; presents with sudden bilious vomiting and requires emergency surgical decompression.

Magnetic resonance cholangiopancreatography — non-invasive MRI-based imaging of the biliary and pancreatic ductal systems; used to evaluate biliary strictures (PSC), choledochal cysts, and biliary anatomy without radiation.

The specific antidote for paracetamol (acetaminophen) overdose; replenishes glutathione stores, preventing accumulation of the toxic metabolite NAPQI; most effective when given within 8–10 hours of overdose.

N-acetyl-p-benzoquinone imine — the toxic metabolite of paracetamol (formed by CYP2E1) that depletes glutathione and causes zone 3 hepatocyte necrosis in overdose; the target of NAC therapy.

A flexible tube inserted through the nostril and advanced through the nasopharynx and oesophagus into the stomach; used for enteral feeding, medication administration, or gastric decompression.

The method for estimating correct NG tube insertion depth: the distance from the tip of the Nose to the Earlobe to the Xiphisternum, approximating the distance from nares to gastric fundus.

Synthetic somatostatin analogue that causes splanchnic vasoconstriction, reducing portal blood flow and portal pressure; first-line pharmacological agent for acute variceal haemorrhage in children.

Dilated submucosal veins at the oesophagogastric junction representing portosystemic collaterals in portal hypertension; rupture causes life-threatening haematemesis.

Upper gastrointestinal endoscopy examining the oesophagus, stomach, and duodenum; diagnostic (bleeding source, biopsy) and therapeutic (band ligation, foreign body removal, haemostasis) indications in children.

Selective 5-HT3 receptor antagonist antiemetic; evidence-based single-dose treatment for vomiting in acute gastroenteritis in children ≥6 months (0.15 mg/kg oral); improves ORS tolerance and reduces hospitalisation.

Home-based oral rehydration for children with no dehydration: 50-200 mL ORS after each loose stool (age-dependent), continue breastfeeding and feeding, return if signs worsen.

Supervised facility-based oral rehydration for SOME dehydration: 75 mL/kg of reduced-osmolarity ORS given over 4 hours, reassessment at 4 hours.

Emergency IV rehydration for SEVERE dehydration: Ringer's Lactate 100 mL/kg total (30 mL/kg rapid then 70 mL/kg); speed varies by age (<12 months: 1h + 5h; ≥12 months: 30min + 2.5h).

Involuntary leakage of liquid stool around a hard fecal impaction, resulting in underwear soiling; a complication of functional constipation with fecal impaction; not voluntary misbehaviour.

Multi-centre consortium that established diagnostic criteria and studied outcomes of FHF in children; PALF trial showed benefit of NAC in non-acetaminophen FHF.

Erythema of the thenar and hypothenar eminences with relative pallor of the palm centre; caused by oestrogen excess from impaired hepatic metabolism; a sign of chronic liver disease.

A standardised training programme for management of paediatric cardiac arrest and emergencies; specifies IO access after 2 IV attempts or 90 seconds in cardiac arrest as first-line emergency vascular access.

Oral lipase/protease/amylase capsules (e.g., Creon) taken with every meal and snack in cystic fibrosis to replace the enzymatic secretion that the diseased pancreas cannot provide; normalises fat digestion and resolves steatorrhoea.

Excretion of acidic urine despite systemic metabolic alkalosis, as seen in hypertrophic pyloric stenosis; occurs because the kidney sacrifices acid-base regulation to maintain intravascular volume (hydrogen ions exchanged for sodium).

Pediatric End-stage Liver Disease score — used to prioritise liver transplant allocation in children under 12 years; based on bilirubin, INR, albumin, age, and growth failure.

D-penicillamine — a copper chelator used as first-line treatment in Wilson disease; can cause paradoxical neurological worsening early in treatment, as well as nephrotoxicity, bone marrow suppression, and lupus-like reactions.

Inflammation of the peritoneum, typically from a perforated hollow organ; presents with board-like rigidity, absent bowel sounds, systemic toxicity; requires immediate surgical management.

The recommended method for confirming NG tube gastric placement: aspiration of gastric contents tested on pH paper; pH ≤5 confirms the tube tip is in the stomach, not the respiratory tract.

Inflammation of a vein, presenting as erythema, warmth, and tenderness along the vein tract, as a complication of IV cannulation; requires removal of the cannula and change of IV site.

Osmotic laxative that retains water in the colonic lumen; first-line agent for both disimpaction (1–1.5 g/kg/day) and maintenance (0.4–0.8 g/kg/day) in paediatric functional constipation per ESPGHAN/NASPGHAN guidelines.

Elevated portal venous pressure >10 mmHg (clinically significant >12 mmHg HVPG); classified as pre-hepatic, intrahepatic, or post-hepatic based on site of obstruction.

Mucosal abnormality of the gastric mucosa in portal hypertension, appearing as a mosaic or snake-skin pattern on endoscopy; can cause chronic occult blood loss.

Persistent small intestinal mucosal damage following acute gastroenteritis, causing secondary malabsorption (particularly lactase deficiency and fat malabsorption); common in malnourished children in low-resource settings.

Prominent Schwalbe line (anterior displacement of the ring of Descemet's membrane) seen on slit-lamp examination; present in >90% of Alagille syndrome patients — a distinguishing ocular sign.

Reversible acute kidney injury from reduced renal perfusion secondary to dehydration; characterised by elevated urea:creatinine ratio (>20:1), urine Na <20 mEq/L, FeNa <1%, and concentrated urine; reverses with rehydration.

The pre-icteric phase of acute viral hepatitis lasting 1–2 weeks before jaundice appears, characterised by non-specific constitutional symptoms (fever, malaise, nausea, anorexia); the peak infectious period for HAV (maximum faecal viral shedding).

Non-selective beta-blocker used in secondary and primary prophylaxis of variceal haemorrhage; reduces cardiac output and causes splanchnic vasoconstriction, lowering portal pressure; dose titrated to 25% reduction in resting heart rate.

Pain on passive extension (or active flexion against resistance) of the right hip; positive when a retrocaecal appendix lies adjacent to the psoas muscle.

A measure of the extrinsic coagulation pathway; reflects the liver's synthetic function (Vitamin K-dependent factors II, VII, IX, X); INR >1.5 with encephalopathy is a criterion for acute liver failure.

Surgical treatment of Hirschsprung's disease: resection of the aganglionic segment and anastomosis of normally innervated proximal bowel to the anus; types include Swenson, Soave, and Duhamel operations.

The narrow canal through the hypertrophied pyloric muscle in HPS; channel length >14-16 mm on ultrasound is diagnostic.

Surgical procedure for hypertrophic pyloric stenosis involving longitudinal incision of the hypertrophied pyloric muscle without entering the mucosa, relieving gastric outlet obstruction.

Pain on sudden release of deep abdominal pressure; indicates peritoneal irritation; in children, may be elicited gently by abdominal percussion as an equivalent.

Reflex relaxation of the internal anal sphincter in response to rectal distension, allowing stool to be sampled at the anal verge; absent in Hirschsprung's disease (demonstrable on anorectal manometry).

WHO-recommended oral rehydration solution with osmolarity of 245 mOsm/L (Na 75 mmol/L, K 20 mmol/L, glucose 75 mmol/L, citrate 10 mmol/L); superior to standard ORS in reducing stool output and duration of diarrhoea.

Effortless, passive return of gastric contents into the mouth without nausea or muscular effort; normal and self-limiting in most infants (physiological gastro-oesophageal reflux).

Surgical anastomosis between the superior mesenteric vein and the intrahepatic left portal vein using a vein graft; restores physiological portal flow to the liver in EHPVO; the preferred definitive surgical option when the intrahepatic left portal vein is patent.

Non-absorbable antibiotic used as adjunct in hepatic encephalopathy; reduces gut bacterial load and ammonia production without systemic absorption.

International consensus diagnostic criteria for functional gastrointestinal disorders in children, including functional constipation; requires symptom duration of ≥1 month for children <4 years and ≥2 months for older children/adolescents.

Most common cause of severe dehydrating gastroenteritis in children under 5 years worldwide; spreads faecal-orally; causes osmotic malabsorption by destroying brush-border enterocytes; preventable by oral rotavirus vaccine in India's NIS.

Pain in the right iliac fossa elicited by palpating the left iliac fossa; positive in appendicitis, indicating peritoneal stretch due to localised peritoneal irritation around the inflamed appendix.

Bedside technique for detecting the liver border by auscultation: scratching sound is louder when transmitted through solid liver and quieter when the scratching finger crosses the liver edge; useful when percussion is unreliable due to bowel gas.

Balloon tamponade device with oesophageal and gastric balloons that compress varices mechanically; used as a bridge to definitive therapy when endoscopic control fails; maximum 24 hours.

Brush-border membrane protein in small intestinal enterocytes that co-transports sodium and glucose from lumen to cell using the electrochemical sodium gradient; remains functional in secretory diarrhoea (cAMP-independent) — the physiological basis of ORS efficacy.

Percussion sign of ascites: the fluid-gas interface in the peritoneal cavity shifts with body position; tympanic centrally and dull laterally when supine, shifting laterally when the patient rolls to one side.

A potent cytotoxin produced by EHEC that binds to Gb3 receptors on intestinal and renal glomerular endothelial cells, inhibiting protein synthesis and triggering thrombotic microangiopathy.

The most common causative bacterium of bacillary dysentery in Indian children; invasive enteric pathogen that penetrates colonic epithelium and causes mucosal ulceration with a very low infective dose.

Well-localised, sharp pain arising from parietal peritoneal irritation; mediated by fast Aδ-fibres via spinal nerves; its precise localisation identifies the inflamed organ or its peritoneal surface.

Dilated cutaneous arterioles with a central feeding vessel and radiating branches resembling a spider's web, found on the upper chest/face in CLD; caused by impaired hepatic oestrogen metabolism.

Aldosterone antagonist diuretic; first-line treatment for ascites in cirrhotic portal hypertension; promotes sodium excretion while retaining potassium; used in combination with furosemide in refractory cases.

Spleen palpable below the left costal margin; measured in centimetres below the left costal margin in the midclavicular line; graded as mild (<5 cm), moderate (5–10 cm), or massive (>10 cm).

Infection of ascitic fluid without an obvious intraperitoneal source, diagnosed by ascitic fluid PMN count >250 cells/µL; treated with ceftriaxone; long-term norfloxacin prophylaxis after first episode.

Fatty stools characterised by pale colour, bulky volume, greasy texture, offensive odour, and tendency to float; a sign of significant fat malabsorption.

The gold-standard diagnostic test for cystic fibrosis using pilocarpine iontophoresis to collect sweat; chloride >60 mmol/L is diagnostic; 30–59 = borderline; <30 = normal.

Ultrasound finding in intussusception — concentric rings on transverse scan representing the intussusceptum within the intussuscipiens; also called the 'doughnut sign'.

A painful, persistent urge to defaecate despite an empty rectum, caused by inflammation of the rectal mucosa; a hallmark clinical feature of dysentery.

Vasopressin analogue that causes systemic and splanchnic vasoconstriction; used in acute variceal haemorrhage in adults; can be used in children as alternative to octreotide.

Twisting of the spermatic cord causing ischaemia of the testis; presents with acute scrotal or lower abdominal pain; absent cremasteric reflex; absent Doppler flow on USG; surgical emergency with 6-hour window for orchidopexy.

Transforming growth factor beta 1 — the principal pro-fibrotic cytokine in hepatic fibrosis; secreted by activated Kupffer cells and hepatocytes, it drives hepatic stellate cell activation and collagen deposition.

The bony prominence on the anterior proximal tibia, just below the knee joint, onto which the patellar tendon inserts; the key anatomical landmark for IO access — the insertion point is 1–2 cm below and medial to it.

Radiologically placed metal stent creating a channel between portal and hepatic vein within liver parenchyma; dramatically reduces portal pressure; used as rescue therapy in adults and selected older children with refractory variceal bleeding or ascites.

Measured simultaneously with anti-tTG IgA to detect selective IgA deficiency (present in 2–3% of coeliac patients), which causes false-negative anti-tTG IgA serology; if low (<7 mg/dL), switch to IgG-based coeliac serology.

The radiological landmark in Hirschsprung's disease where the narrow aganglionic segment meets the dilated proximal normally innervated bowel; seen on contrast enema as a funnel-shaped change in calibre.

Triangular percussion area on the left anterior chest bounded by the 6th rib superiorly, left anterior axillary line laterally, and left costal margin inferiorly; normally tympanic; dullness suggests splenomegaly.

Triethylenetetramine — a copper chelator used as an alternative to penicillamine in Wilson disease; better tolerated, preferred when neurological disease is prominent to avoid paradoxical worsening.

Series of hepatic enzymatic reactions converting toxic ammonia to non-toxic urea for renal excretion; completely lost in FHF, leading to hyperammonaemia and HE.

Hydrophilic bile acid that displaces toxic bile acids, enhances bile flow, and has hepatoprotective effects; used post-Kasai in biliary atresia, in primary sclerosing cholangitis, and in other cholestatic conditions.

The histological hallmark of established coeliac disease (Marsh 3); the small intestinal villi are flattened, dramatically reducing the absorptive surface area and causing pan-malabsorption.

Poorly localised, crampy or dull abdominal pain arising from hollow organ distension or ischaemia; mediated by C-fibres via sympathetic afferents; perceived as periumbilical regardless of organ involved.

Forceful expulsion of gastric or intestinal contents through the mouth, coordinated by the medullary vomiting centre and involving active contraction of abdominal and diaphragmatic muscles.

Autosomal recessive disorder of copper metabolism (ATP7B gene) causing copper accumulation in liver, brain, and kidneys; can present as FHF in children and adolescents with paradoxically low alkaline phosphatase.

An autosomal recessive disorder of copper metabolism (ATP7B gene mutation) causing hepatic copper accumulation; can present as acute hepatitis with haemolytic anaemia in children/adolescents; Kayser-Fleischer rings (slit-lamp) and low serum caeruloplasmin are diagnostic.

Voluntary contraction of the external anal sphincter and pelvic floor to defer defecation, usually to avoid pain; the primary driver of the self-perpetuating functional constipation cycle.

WHO/UNICEF-recommended adjunct therapy in acute diarrhoea; reduces duration and severity; dose: 20 mg/day (>6 months) or 10 mg/day (<6 months) for 14 days, continued after diarrhoea resolves.