Ilio-inguinal Nerve Entrapment Syndrome: A Cause of Abdominal Pain.

The ilio-inguinal nerve is vulnerable to entrapment at its exit from the external oblique muscle medial to the anterior superior iliac spine. When entrapment occurs, patients complain of pain either around the exit point or over the L 1 dermatome. Four case histories illustrate, paradoxically, how easy and how difficult it can be to diagnose this condition.