Colorectal Cancer & Diverticular Disease
Investigate altered bowel habit and bleeding while separating uncomplicated disease from obstruction, perforation and sepsis.
Quick revision ↓ Medical Dictionary
01Recognise alarm features
Rectal bleeding, iron-deficiency anaemia, persistent bowel-habit change, weight loss or a mass can indicate colorectal disease. Symptoms overlap with benign conditions, so examination and the local referral pathway are important. Finding haemorrhoids does not prove that they explain all bleeding. Consider family history and inherited risk, and communicate when symptoms persist despite an initial reassuring investigation.
02Investigate and stage
Colonoscopy or another suitable colonic investigation assesses lesions and permits biopsy where appropriate. FIT can support selected referral pathways but must be interpreted with symptoms and safety-netting; persistent concern can require further assessment despite a low result. Confirmed cancer requires staging and multidisciplinary review. Rectal cancer needs attention to local pelvic anatomy because it affects operative and preoperative treatment planning.
03Recognise cancer emergencies
A tumour may present with obstruction, perforation or major bleeding rather than a routine clinic referral. Resuscitation and source control take priority, with definitive options selected according to stability, anatomy and expertise. A stoma or staged approach may be necessary. Avoid promising immediate primary anastomosis before the team has assessed contamination, perfusion and the patient's physiological reserve.
04Distinguish diverticular presentations
Diverticulosis can be incidental, whereas diverticulitis produces inflammation that may be uncomplicated or complicated by abscess, perforation, fistula or obstruction. Left-sided pain and fever are suggestive but not diagnostic. Imaging is selected according to severity and uncertainty. Immunosuppression, systemic illness or failure to improve should lower the threshold for specialist assessment rather than routine repeated treatment without review.
05Plan continuing care
Treatment depends on complexity and includes selected conservative care, antibiotics when indicated, drainage or surgery. Explain recurrence and warning symptoms without implying that every episode requires resection. After recovery, arrange appropriate evaluation for alternative pathology when indicated. Cancer follow-up includes pathology review, staging decisions, bowel function, stoma support and the patient's goals, with named responsibility for each next step.
High-Yield Revision
- Haemorrhoids do not exclude a proximal bleeding source.
- Cancer emergencies need physiological priorities before definitive staging.
- Complicated diverticulitis may require drainage or surgery.
Common Pitfalls
- Do not ignore persistent alarm symptoms after a low-risk initial test.
- Do not promise an anastomosis before assessing contamination and physiology.
References & Further Reading
Read the relevant guideline sections alongside these original clinical teaching cases. Local pathways, available services and individual patient factors determine care.
Reference review: 27 September 2026. Consult current local protocols for prescribing, procedures and escalation.