A 60-year-old-woman presented to our hospital with right lower quadrant pain. A contrast-enhanced CT scan revealed approximately 7cm low density area with air-fluid level, close to the ascending colon. Patient was diagnosed with intra-abdominal abscess and was started on intravenous antibiotics. CT guided percutaneous drainage was performed. However, there was continuous extravasation of contrast medium into the colon upon follow-up contrast examination. Five days later, abscess was noted to be smaller than before, however, extravasation of contrast medium was still observed. Fistula formation from the abscess cavity leading to the ascending colon was noted. Colonoscopy examination revealed erythema and swelling of the diverticulum in the ascending colon. When we injected indigo carmine from the drain tube, liquid flowed the diverticulum. We closed the diverticulum using 8 short clips. Patient had an uneventful course after hospital discharge without recurrence for more than 1 year, and the diverticulum resolved.
