Gastrointestinal
perforation: clinical and MDCT clues for identification of aetiology. 75-year-old patient with perforation secondary to obstructive ileus in the setting of rectal cancer (not shown). Axial image (lung window) shows leaked faecal material (fm), abutting the mesenteric root and surrounding ileal loops (arrows), pneumoperitoneum (p), and the perforation site (arrowhead) as a wall discontinuity of the descending colon (dc)