Ask the surgeon, not an uninvolved physician. Some pain is expected. A lot of pain is a red flag.

Carl Lauter, MD

Your son could feel pain later after an appendectomy for several reasons. First, the sources of pain differ given the time frame postoperatively. If the pain occurs within days of his/her surgery, it can be due to incisional postoperative pain from stretching of abdominal wall and abdominal wall muscles and/or the residual effects of infusing gas in the abdomen if he/she underwent laparoscopic appendectomy. If the period of time is from 1-3 weeks, he may be feeling the pain from healing (inflammatory effects of healing and scar tissue) and he may feel pain or actually only notice it with deep breathing or exercise such as catching his breath. This source of pain can be from the inflammation from scarring as he heals, and some pain maybe neurogeneic since cutaneous sensory nerves are divided with an incision (usually more prominent with open surgery than laparoscopic).