This patient has had significant traumatic injury to the groin. Note the hypodense densities representing locules of air trapped within the right iliac fossa. 

Also note the heterogeneous fluid surrounding the bladder and sitting dependently within the pelvis. It is likely that the initial traumatic event caused trauma to the lower small bowel mesentery, which has tracked down from the peritoneum to sit within the pelvis. It is lying dependently in the uterovesical pouch and the rectouterine pouch.

Case contributed by A/Prof. Pramit Phal.