Gastrointestinal
Core concepts
Organise by symptom pattern: upper GI bleeding (peptic ulcer, varices, Mallory-Weiss), dyspepsia and Helicobacter pylori eradication, and inflammatory versus infectious diarrhoea. Know the red flags that mandate endoscopy or imaging - weight loss, dysphagia, anaemia, age over a threshold, nocturnal symptoms. Understand the pathophysiology and management of acute pancreatitis (gallstones and alcohol), appendicitis, diverticulitis, and bowel obstruction. Recognise coeliac disease, inflammatory bowel disease phenotypes (Crohn transmural versus ulcerative colitis mucosal), and the approach to chronic constipation and irritable bowel syndrome.
Traps
Questions test resuscitation before investigation: a bleeding patient needs two large-bore lines and cross-match before endoscopy. Do not give oral contrast or delay surgery for perforation. Distinguish upper from lower bleeding by presentation (haematemesis/melaena versus haematochezia) but remember brisk upper bleeds can present with fresh blood per rectum. In pancreatitis, amylase is neither diagnostic alone nor a severity marker; use clinical scoring and look for organ failure.
Worked example
A 45-year-old with epigastric pain radiating to the back, vomiting, and a history of heavy alcohol use has raised lipase. Diagnosis: acute pancreatitis. Rule of thumb: treat with aggressive intravenous fluids, analgesia, and early enteral nutrition; do not give prophylactic antibiotics unless there is infected necrosis or a confirmed infection.