A 41-year-old female patient with medical history of bipolar disorder, on topiramate and quetiapine for several years and on sertraline for the last 4 months, presented to the emergency department with diarrhea (6–8 bowel movements per day, watery stools, no blood) and weight loss (20 Kg) for the past 2–3 months. Physical examination revealed mild discomfort on palpation of the right lower quadrant without any peritoneal signs. Laboratory results showed mild and isolated leucocytosis (11 500/uL), CRP was within normal range.