Abstract
Capecitabine has been used for triple-negative metastatic breast cancers both as monotherapy and in combination with other agents. However, its gastrointestinal side effects are one of the biggest challenges for its patient compliance, and often result in permanent drug withdrawal. There have been reports of it causing enterocolitis (mainly terminal ileitis) and even ischaemic colitis, but it has not frequently been directly associated with Clostridium difficile infection. We describe a case of a 65-year-old woman with triple-negative breast cancer on palliative capecitabine who presented with blood-streaked watery diarrhea and abdominal pain and was diagnosed with chemotherapy-induced severe colitis with superimposed Clostridium difficile infection.