CT scan (abdomen) (before treatment) showing status post left lower quadrant colostomy. Left lower quadrant colostomy and large peristomal hernia containing fat and small bowel lobes are seen. Moderate inflammatory changes are again seen surrounding the sigmoid colon suggestive of diverticulitis. Interval increase in the size of the fluid collection or abscess formation at or adjacent to the sigmoid colon since the previous exam measures approximately 5.5 × 4.3 cm (arrow). There is either extension or additional collection also seen to the left of the colon measuring 3.6 × 3.2 cm (arrow). There are mildly enlarged mesenteric lymph nodes seen at the left lower abdomen.