At other times a few tests are conducted.
Blood tests to rule out anemia, stool test to look for white
blood cells, sigmoidoscopy, colonoscopy etc are used to diagnose ulcerative colitis. Braium meal and follow through, endoscopy etc are done to rule out GERD, Crohn’s disease etc. Irritable bowel syndrome is diagnosed by elimination of other causes. Gluten is a complex protein present in four main grains---wheat, rye, barley and oats.