What Causes Chronic Abdominal Pain And Constipation Post An Appendectomy?

My 22 year old son is experiencing major symptoms after an appendectomy. 8 months later he still has severe chronic abdominal pain, can t pass a solid stool, always feels constipated, nothing helps for pain. When he walks his rectum hurts. He is bedridden with dark thoughts. He has had xray of stomach, endoscopy and several blood and stool tests, all normal. He is always nauseous and has no appetite.too many er visits to recall, always sent home in pain. Referred to a colorectal surgeon and pain management clinic, but can t get in until end of july. He can t stand another day of this nightmare pain. We can we do?