I had a rectal resection and temporary ileostomy last December. On June 20th my ileostomy was reversed.  My abdomen, which has always been totally flat is now distended like a pregnant womans.  I am a 65 year old slim male who does weight training and cardio at least 5 days per week.  What might be causing this abdominal swelling?  Thanks.
HI. With the history you have provided, the commonest reason is intestinal obstruction. Get the following investigations done. X-ray of the abdomen in standing position to confirm intestinal obstruction. Exploratory laparotomy by open route or by laparoscopy can give you the diagnosis as well as treatment by releasing the adhesions