What Causes Upper Abdominal Pain Post Bilateral Renal Bypass Surgeries?

My husband has had 2 bilateral renal bypasses in which the incision ran the entire length of his stomach. He now has pain in his upper abdomen, sometimes severe. They have ruled out vascular as reasons for pain. They are going to do an upper GI to make sure there isn t something in his stomach causing the pain. When the doctor did the last renal bypass, he said that my husband had severe scar tissue built up. His doctor thinks this may be the cause of his pain. I have read about lysis of adhesions. Can you tell me more about it and how it is diagnosed? The last CT he had did not show any scar tissue, but they were looking at the vascular. Nothing else was noted in the report. He has been in pain that has gotten progressively worse since his first renal bypass in 2003. The last four or five years have been quite severe. He went to a pain management clinic and the doctor said the source is too deep for them to do a pain block. Any information you can provide would be greatly appreciated.