Master Gastroenterology
for MRCP Part 1

What the MRCP Part 1 Tests in Gastroenterology

MRCP Part 1 Gastroenterology tests the ability to manage common and emergency presentations: dysphagia, dyspepsia, upper and lower GI bleeding, diarrhoea, jaundice, and chronic liver disease. Candidates must differentiate between organic and functional disorders, apply the Bristol Stool Chart, and use scoring systems like Rockall, Child-Pugh, and MELD. Knowledge of first-line treatments for H. pylori (clarithromycin-based triple therapy, with bismuth quadruple for resistant cases), PPI prescribing in GORD, and management of IBD (5-ASAs, anti-TNF, JAK inhibitors) is essential. The exam also covers coeliac serology (tTG-IgA), iron-deficiency anaemia investigation, and pancreatic cancer (CA19-9, CT staging). Liver topics include viral hepatitis serology (anti-HCV, HBsAg, HBeAg), NAFLD/NASH diagnosis (FibroScan, FIB-4), and variceal haemorrhage management (terlipressin, banding, antibiotics).

High-Yield Concepts

• Rockall Score for Upper GI Bleeding: Pre-endoscopy Rockall uses age (>60, >80), shock (no shock, tachycardia, hypotension), and comorbidities (none, cardiac/renal/liver failure, metastatic cancer). Score ≥5 predicts high mortality. Post-endoscopy adds stigmata of recent haemorrhage (active bleeding, visible vessel, adherent clot). First-line treatment: terlipressin and prophylactic antibiotics (ceftriaxone) for variceal bleeds.
• H. pylori Eradication Regimens: First-line: 7-day triple therapy (omeprazole 20 mg BD, amoxicillin 1 g BD, clarithromycin 500 mg BD). If clarithromycin resistance suspected or prevalence >15%, use bismuth quadruple therapy (bismuth subsalicylate, metronidazole, tetracycline, PPI) for 10-14 days. Test of cure: 13C-urea breath test or stool antigen, at least 4 weeks after completing antibiotics.
• Child-Pugh Score in Cirrhosis: Scored using bilirubin, albumin, INR, ascites, and encephalopathy. Class A (5-6 points), B (7-9), C (10-15). Guides prognosis and treatment decisions: variceal screening (OGD at diagnosis), TIPS for refractory ascites, and liver transplant listing (MELD >15).
• Bristol Stool Chart for IBS: Type 1-2: constipation (IBS-C); Type 6-7: diarrhoea (IBS-D). Rome IV criteria: recurrent abdominal pain at least 1 day/week for 3 months, associated with defecation, change in stool frequency or form. First-line: antispasmodics (mebeverine, hyoscine), loperamide for diarrhoea, linaclotide for constipation.
• Coeliac Disease Diagnosis: Serology: IgA tTG (or IgG tTG if IgA deficient). Positive result requires duodenal biopsy (Marsh grade ≥2). HLA DQ2/DQ8 testing useful if serology negative but high suspicion. Management: strict lifelong gluten-free diet, annual monitoring of tTG, and check for associated conditions (type 1 diabetes, autoimmune thyroiditis).
• Inflammatory Bowel Disease: Anti-TNF Therapy: Infliximab (5 mg/kg IV at weeks 0, 2, 6, then 8-weekly) for moderate-to-severe Crohn’s or UC. Adalimumab (subcutaneous) as alternative. Check TB (Quantiferon, CXR) and hepatitis B serology before starting. Monitor for infusion reactions, infections, and skin cancers.
• Acute Pancreatitis: Glasgow Score: Assessed within 48 hours: M-ARDS (age >55), O-xygen (<60 mmHg), C-alcium (<2.0 mmol/L), R-enal (urea >16 mmol/L), A-lbumin (<32 g/L), S-ugar (glucose >10 mmol/L), L-DH (>600 IU/L). Score ≥3 predicts severe pancreatitis. Management: aggressive IV fluids (Hartmann’s), analgesia, CT with contrast if no improvement at 48-72 hours, and ERCP for cholangitis/obstruction.
• Hepatitis B Serology Interpretation: HBsAg positive = chronic infection. HBeAg positive = high viral replication (treatment with tenofovir or entecavir indicated if ALT elevated). Anti-HBe positive = seroconversion (lower replication). HBV DNA >2000 IU/mL with ALT >2x ULN triggers treatment. Screen for hepatocellular carcinoma with 6-monthly ultrasound and AFP.

Common Traps in Gastroenterology Questions

• Confusing the Rockall score (pre-endoscopy) with the Glasgow-Blatchford score (for need for intervention); Rockall predicts mortality, Blatchford predicts need for transfusion/endoscopy.
• Assuming a negative H. pylori stool antigen test after treatment is always reliable: must wait 4 weeks after antibiotics and 2 weeks after PPI to avoid false negatives.
• Forgetting that in acute pancreatitis, CT is not indicated within the first 48 hours unless diagnosis uncertain; early CT can underestimate necrosis.
• Using the Bristol Stool Chart to diagnose IBS without first excluding coeliac disease with tTG-IgA and checking a full blood count for iron deficiency.
• Treating variceal bleeding with octreotide alone without terlipressin: terlipressin is the preferred vasoactive drug in the UK (NICE guidelines).
• Missing the need for hepatitis B core antibody (anti-HBc) testing in patients on anti-TNF therapy; isolated core antibody can indicate occult HBV.

How to Revise Gastroenterology for the MRCP Part 1

Prioritise memorising scoring systems (Rockall, Child-Pugh, MELD, Glasgow) and their specific cut-offs. Practice interpreting liver function tests (e.g., ALP > GGT suggests cholestasis; ALT > AST in viral hepatitis, reversed in alcoholic hepatitis). Focus on antibiotic choices: ceftriaxone for variceal bleeding, ciprofloxacin for spontaneous bacterial peritonitis, metronidazole for C. difficile. Questions often present a clinical vignette with a single lab value missing (e.g., INR in Child-Pugh) and ask for the next step. Revise NICE guidelines for dyspepsia (test and treat H. pylori, then PPI trial) and for colorectal cancer screening (FIT test threshold 10 µg Hb/g). Spend time on IBD drug side effects (e.g., thiopurine-induced pancreatitis, anti-TNF demyelination).

Practise it: MedLumen has 54 Gastroenterology questions for the MRCP Part 1, each with a full explanation and references.