Clozapine induced megacolon with stercoral colitis successfully managed with conservative treatment

Abstract Clozapine is a second-generation antipsychotic with proven efficacy in treatment-resistant schizophrenia patients; however, it requires careful monitoring due to its serious side effects. While its most well-known side effect is agranulocytosis, gastrointestinal hypomotility is a less recognized but potentially fatal complication. This article presents a case of a 37-year-old male patient weighing 73 kg who had been taking 300 mg of clozapine daily for two years and developed megacolon and stercoral colitis as a result of clozapine-induced gastrointestinal hypomotility. The patient presented to the emergency department after three months of constipation complaints; abdominal computed tomography revealed marked colonic dilatation and fecal impaction. Clozapine treatment was discontinued, conservative treatment was administered, and clinical improvement was achieved. The patient was discharged completely recovered without the need for surgical intervention. This case highlights the rare but serious gastrointestinal side effects of clozapine and demonstrates that early diagnosis and appropriate treatment can prevent mortality. It is clinically critical to inquire about constipation symptoms in patients using clozapine and to perform early evaluation for megacolon.