The commonest site of traumatic small bowel perforation is the jejunum (near the ligament of Trietz / DJ flexure), as in this case. However, It is often the case that this cannot be identified on CT. In fact, the larger the pneumoperitoneum the harder it often is to localized the site of a perforation.

This is one of the classical mechanisms of injury for a jejunal perforation. Blunt abdominal injury from hitting the handle bars after a fall from a bicycle. It is more typically observed in children.

The intra-operative images show the site of the injury, although the site is difficult if not impossible to identify on the CT.