ROSH Gastrointestinal Practice Exam

The numbness about the "beltline" in a patient post-inguinal hernia surgery may indicate irritation of which nerve?

1. Iliohypogastric

2. Lateral femoral cutaneous

3. Obturator

4. Pudendal

The correct answer is: Iliohypogastric

The numbness about the "beltline" following inguinal hernia surgery is most commonly associated with irritation of the iliohypogastric nerve. This is due to the anatomical location and the typical nerve damage that can occur during surgical procedures in this region. The iliohypogastric nerve supplies sensation to the skin of the lower abdominal wall, particularly the areas around the beltline. Irritation or injury to this nerve during surgery can lead to sensory deficits that manifest as numbness or altered sensation in the corresponding dermatomes. This can occur due to direct trauma, compression from surgical instruments, or scar tissue formation postoperatively. The other nerves listed have different functions and innervate different areas. The lateral femoral cutaneous nerve primarily provides sensation to the skin of the lateral thigh, the obturator nerve is responsible for innervating the medial thigh and providing sensation to that region, while the pudendal nerve is crucial for perineal sensation and function. Therefore, these nerves would not be responsible for sensory changes specifically located at the beltline.