Case contributed by RMH Core Conditions


Post colonoscopy

Patient Data

Age: 75 years
Gender: Female

Several bowel loops in the upper pelvis are surrounded by free gas (Rigler sign). Further free gas in retroperitoneum adjacent to aorta and inferior vena cava.

Bowel gas distribution otherwise normal. No abnormally dilated bowel loops seen.

Annotated image
  • red arrow = free retroperitoneal gas outlining the liver/IVC
  • yellow arrow = free retroperitoneal gas outlining the aorta
  • blue arrow = Rigler sign of free pelvic gas outlining the rectosigmoid junction

There is a large amount of free gas located with in the pelvis and retroperitoneal spaces. This appears to be arising from a perforation of the mid sigmoid colon.

At this point, the sigmoid colon lumen appears significantly narrowed. Contrast is present throughout the large bowel, extending into the rectum.

There is no obvious point of contrast extravasation from the bowel lumen. No free intraperitoneal fluid. The presence of pelvic fluid is difficult to identify due to streak artefact from the hip replacements.

Case Discussion

Patient proceeded to an ultra-low anterior resection (ULAR) and histopathology confirmed sigmoid colon as perforated with diverticulitis complicated by abscess. 

PlayAdd to Share

Case information

rID: 33609
Published: 18th Jan 2015
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.