Colorectal Surgery
What the exam tests
This domain tests colorectal cancer presentation and staging, rectal bleeding, inflammatory bowel disease, diverticular disease, obstruction and anorectal conditions.
Core rules
- Iron-deficiency anaemia in an older adult and a change in bowel habit require colonoscopy, not empirical haemorrhoid treatment.
- Colorectal cancer staging uses TNM; rectal cancer also needs MRI for mesorectal fascia assessment, and local excision is reserved for selected early lesions.
- Rectal cancer surgery aims at total mesorectal excision with clear margins; low anterior resection may require a temporary defunctioning stoma.
- Anastomotic leak presents with tachycardia, pain, fever, ileus or peritonitis; CT with contrast and urgent reoperation may be needed.
- Diverticulitis with abscess or generalised peritonitis requires drainage or resection; Hinchey staging guides urgency.
- In IBD, surgery is considered for failure of medical therapy, dysplasia, stricture, fistula or toxic megacolon.
Worked example
A 58-year-old has a six-week change in bowel habit, fatigue and iron-deficiency anaemia. Colonoscopy shows a caecal adenocarcinoma; biopsy confirms invasive cancer. Staging CT shows no distant disease. After MDT review, a right hemicolectomy with primary anastomosis is performed, and the specimen yields adequate lymph nodes for staging.
Traps
Attributing rectal bleeding to haemorrhoids without examination; omitting a digital rectal examination; failing to complete staging before surgery; and missing anastomotic leak because tachycardia is attributed to pain.