Gastroenterology
Gastroenterology tests resuscitation and risk stratification in GI bleeding, cirrhosis complications, pancreatitis severity, inflammatory bowel disease, and safe prescribing in liver disease. The exam emphasizes bedside decisions and procedure timing.
Core rules
- Upper GI bleed: resuscitate; calculate Glasgow-Blatchford score; give PPI; endoscopy within 24 hours after stabilization. Variceal bleed: vasoactive drug plus prophylactic antibiotics plus band ligation.
- Ascites: perform diagnostic paracentesis. SAAG ≥1.1 g/dL indicates portal hypertension. Spontaneous bacterial peritonitis (SBP) if ascitic PMN ≥250/mm3: IV third-generation cephalosporin plus albumin.
- Acute pancreatitis: lipase >3× upper limit of normal; fluids, analgesia, early oral feeding; severity by organ failure; avoid prophylactic antibiotics.
- IBD: ulcerative colitis is continuous colonic inflammation; Crohn disease shows skip lesions and transmural inflammation. Screen for TB and hepatitis before biologics; steroids are not maintenance therapy.
- Clostridioides difficile: oral vancomycin or fidaxomicin; stop unnecessary antibiotics; avoid antimotility drugs.
Worked example
A 52-year-old with cirrhosis and ascites has fever 38.5°C and abdominal pain. Diagnostic paracentesis shows PMN 400/mm3 and SAAG 1.4 g/dL. This is SBP: give IV cefotaxime and albumin 1.5 g/kg on day 1, then 1 g/kg on day 3; start secondary prophylaxis and avoid NSAIDs. Do not wait for culture results before treating.
Traps
- Failing to perform paracentesis in cirrhotic ascites with fever.
- Misinterpreting SAAG or calculating it incorrectly.
- Giving NSAIDs in cirrhosis.
- Routine antibiotics in pancreatitis.
- Antimotility drugs in C. difficile colitis.