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Clozapine Ileus — MRCPsych Paper B MCQ

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ModerateSchizophrenia & PsychosisClozapine IleusMRCPsych Paper B

A 46-year-old patient taking clozapine has not opened their bowels for 8 days. They now have progressive abdominal pain and distension, and bowel sounds are absent. What is the most appropriate immediate management?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: C — Arrange immediate acute medical assessment for suspected ileus or bowel obstruction and withhold clozapine

Explanation lettering: C = shown as A · E = shown as B · B = shown as C · A = shown as E

Option B is correct. Eight days without a bowel motion, progressive abdominal pain, distension and absent bowel sounds are emergency features of clozapine-induced gastrointestinal hypomotility with possible ileus or bowel obstruction, rather than uncomplicated constipation. RCPsych’s Wim’s Protocol recommends urgent abdominal imaging, blood tests and surgical review for suspected clozapine-related obstruction; clozapine should be stopped when there are significant surgical concerns. The MHRA and SmPC also warn that these complications can be fatal and that paralytic ileus is a contraindication. Options A and E are inappropriate because routine constipation measures must not delay emergency assessment. Option C normalises a potentially fatal adverse effect. Option D is inadequate because dose reduction and routine review do not address an acute abdominal emergency.

Reference: Royal College of Psychiatrists, Wim’s Protocol: for the safe prescribing and monitoring of clozapine, section on constipation and urgent or emergency symptoms, 2026. https://www.rcpsych.ac.uk/docs/default-source/improving-care/wims-protocol/wims-protocol-2026.pdf