AIM OSCE / OSPE • FINAL YEAR MBBS
Station 10 — Lower GI Bleeding, Inflammatory Bowel Disease & Colorectal Cancer
GIT Module • Final Year MBBS • Medicine / Surgery
Rapid Revision • Clinical Skills • Practical Skills • Viva
🎯 Candidate Task
A patient presents with recurrent bleeding per rectum and altered bowel habits. Perform a focused clinical assessment, interpret the supplied endoscopic, histological and imaging findings, identify the likely diagnosis and complications, and outline appropriate surveillance, management and referral decisions.
⚡ Model Station Answer
Assessment: Establish bleeding quantity and color, bowel habit changes, abdominal pain, urgency, tenesmus, weight loss, anemia symptoms and hemodynamic stability.
Differentials: Consider hemorrhoids, fissure, inflammatory bowel disease, diverticular bleeding, polyps and colorectal cancer.
IBD interpretation: Continuous inflammation beginning at the rectum favors ulcerative colitis; skip lesions, ileal involvement or fistulae favor Crohn’s disease.
Complications and surveillance: Recognize severe bleeding, toxic megacolon, perforation, strictures, fistulae and extraintestinal manifestations. Long-standing colonic IBD requires appropriate dysplasia surveillance.
Colorectal malignancy: Colonoscopy with biopsy establishes diagnosis; contrast-enhanced staging imaging and rectal MRI when indicated guide multidisciplinary treatment and surgical referral.
🔎 How to Perform / Approach
- Introduce and assess stability: Confirm identity, obtain consent, assess pulse, blood pressure, pallor and signs of significant blood loss. Escalate immediately if unstable.
- Take a focused history: Ask about fresh or dark rectal bleeding, diarrhea, constipation, mucus, urgency, tenesmus, abdominal pain, weight loss, family history and medication use. Identify persistent bowel habit change and unexplained anemia as warning features.
- Perform focused examination: Assess hydration, pallor, abdominal tenderness, distension, masses and perianal disease. Explain the need for a chaperoned digital rectal examination when appropriate.
- Interpret investigations: Review CBC, inflammatory markers, stool studies and fecal calprotectin where relevant. Interpret colonoscopy and histology: continuous rectal disease in ulcerative colitis versus discontinuous inflammation in Crohn’s disease.
- Identify complications and surveillance needs: Assess for toxic megacolon, severe colitis, perforation, obstruction, fistulae and extraintestinal involvement. Identify long-standing colonic IBD requiring surveillance colonoscopy, usually beginning approximately 8 years after symptom onset, depending on risk.
- Evaluate suspected colorectal cancer: Identify an endoscopic mass and confirm malignancy histologically. Review contrast-enhanced CT chest/abdomen/pelvis, baseline CEA and pelvic MRI for rectal cancer; determine referral for multidisciplinary staging and treatment planning.
- Decide management and referral: Stabilize significant bleeding, arrange urgent review for complications or suspected malignancy, and initiate appropriate gastroenterology/colorectal surgical referral. Explain the findings, proposed investigations, treatment pathway and follow-up.
📝 Important Viva Questions
1. What are important red flags in a patient presenting with bleeding per rectum?
Answer: Hemodynamic instability, persistent bleeding, unexplained weight loss, iron-deficiency anemia, altered bowel habits and a palpable mass.
2. How do you differentiate ulcerative colitis from Crohn’s disease on colonoscopy?
Answer: Ulcerative colitis typically shows continuous inflammation beginning in the rectum, whereas Crohn’s disease shows skip lesions, deeper ulceration and possible ileal involvement.
3. Name important intestinal and extraintestinal complications of inflammatory bowel disease.
Answer: Intestinal complications include toxic megacolon, perforation, strictures and fistulae. Extraintestinal manifestations include arthritis, uveitis and erythema nodosum.
4. When should colorectal cancer surveillance begin in patients with long-standing ulcerative colitis?
Answer: Surveillance colonoscopy generally begins about 8 years after onset of colonic disease, with intervals individualized by risk; isolated proctitis usually does not require IBD-specific surveillance.
5. What investigations confirm and stage suspected colorectal cancer?
Answer: Colonoscopy with biopsy confirms malignancy. Contrast-enhanced CT chest, abdomen and pelvis evaluates spread, while pelvic MRI provides local staging for rectal cancer.