A hernia can slide in and out of the anatomic location, particularly when smaller. Therefore, a CT scan may not indicate the hernia if it is not out of position at the time that the scan is done. The findings on physical examination, including trying to reproduce the activity that causes the hernia to pass, is the best way to detect a hernia in this circumstance. A general surgeon would be the appropriate specialist to see for this evaluation.
An OBGyn may be able to detect it, but a general surgeon has more experience in evaluating and managing hernias.