Gastroenterology & Nutrition

Massive hepatocyte necrosis in a liver with no pre-existing disease strips out clotting-factor synthesis and ammonia clearance, so coagulopathy and encephalopathy appear together within days to weeks.

Acute pancreatitis is pancreatic inflammation with local and systemic inflammatory consequences; diagnose it clinically and biochemically, treat early with monitored supportive care and enteral nutrition, and prevent recurrence by addressing the cause.

Alcohol-related liver disease ranges from reversible steatosis through alcohol-related hepatitis to cirrhosis; assess both the liver stage and alcohol-use disorder because abstinence, nutrition and specialist care change prognosis at every stage.

An immune-mediated response to dietary gluten that injures the small-bowel mucosa and causes gastrointestinal or extraintestinal disease; confirm it while gluten is being eaten before starting a lifelong gluten-free diet.

Constipation is unsatisfactory defaecation because stools are infrequent, hard, difficult or incomplete; most is functional or medication-related and responds to a stepwise laxative plan, but obstruction, impaction and colorectal-cancer symptoms must be recognised before routine treatment.

Patchy inflammation of any part of the gut from mouth to anus that extends through the full thickness of the bowel wall, producing strictures, fistulae and abscesses.

Reflux of gastric contents across an ineffective gastro-oesophageal barrier causes troublesome symptoms or mucosal injury; the clinical priority is to recognise alarm features, treat typical disease safely, and investigate persistent or unexplained symptoms objectively.

Hepatocellular carcinoma (HCC) is a primary hepatocyte cancer usually arising in cirrhosis or chronic hepatitis B; early detection and treatment must account for both tumour burden and the reserve of the underlying liver.

A chronic disorder of gut-brain interaction diagnosed positively from abdominal pain related to defaecation or altered stool pattern, once relevant red flags and targeted tests have been addressed.

Irreversible replacement of normal liver architecture by fibrous septa and regenerative nodules causes both failing synthetic function and obstructed blood flow, so every complication is one of these two mechanisms playing out.

Mallory-Weiss syndrome is an upper-GI bleed from a longitudinal mucosal tear at the gastro-oesophageal junction, classically causing haematemesis after forceful vomiting or retching; most tears stop spontaneously, but the patient still needs acute upper-GI-bleed risk assessment.

Malnutrition (undernutrition) is inadequate intake, absorption or use of energy, protein or micronutrients that impairs function and clinical outcomes; identify it with validated screening, find the cause and provide safe, individualised nutrition support.

Metabolic dysfunction-associated steatotic liver disease (MASLD, formerly NAFLD) is hepatic steatosis with cardiometabolic risk; most people are asymptomatic, so the clinical priority is identifying advanced fibrosis and reducing liver and cardiovascular risk.

Oesophageal varices are portosystemic collaterals, usually caused by cirrhosis, that can rupture and cause life-threatening upper gastrointestinal haemorrhage; suspected variceal bleeding needs simultaneous resuscitation, vasoactive treatment, antibiotics and urgent endoscopic control.

Pancreatic cancer is most often an exocrine ductal adenocarcinoma; it may present with obstructive jaundice, weight loss, upper-abdominal or back pain, new diabetes or malabsorption, and treatment depends on specialist staging and whether the tumour is resectable.

A gastric or duodenal mucosal breach occurs when H. pylori, NSAIDs or another insult overwhelms mucosal defence; the high-yield priorities are cause-directed treatment and early recognition of bleeding, perforation, obstruction and gastric malignancy.

Rectal prolapse is descent of rectal tissue through or within the anal canal, ranging from internal intussusception to external full-thickness prolapse; it causes a proluding mass, mucus, bleeding, obstructed defaecation or faecal incontinence and needs urgent review if it is irreducible, dusky or heavily bleeding.

Spontaneous bacterial peritonitis (SBP) is infection of ascitic fluid without a surgically treatable intra-abdominal source, usually in advanced cirrhosis; diagnose it promptly with ascitic neutrophil counting and treat immediately with context-appropriate antibiotics, renal-protective albumin when indicated and specialist follow-up.

Toxic megacolon is acute non-obstructive colonic dilatation accompanied by systemic toxicity, usually complicating acute severe ulcerative colitis or severe infection such as C. difficile; it is a time-critical colorectal emergency because the inflamed colon can perforate.

A chronic inflammatory colitis that usually begins in the rectum and extends continuously proximally, producing bloody diarrhoea and urgency; severity determines whether the pathway is outpatient induction, specialist escalation or acute severe colitis admission.

Bleeding above the ligament of Treitz, where the lesion (an acid-eroded artery or a ruptured portal-hypertensive varix) decides which of two entirely different drug pathways the patient needs.

Infection and inflammation of the liver caused by hepatitis A, B, C, D or E, ranging from self-limiting acute illness to chronic infection with cirrhosis, liver failure and hepatocellular carcinoma.

Volvulus is twisting of bowel around its mesentery, causing a closed-loop obstruction and threatening the blood supply; sigmoid volvulus may be detorted endoscopically when uncomplicated, whereas caecal and paediatric midgut volvulus generally require urgent surgical management.