Celiac is an autoimmune disorder. Ingesting anything that contains gluten which is a protein found in wheat, barley, etc. (not oatmeal - but cross contamination can happen). Some people have a "wheat sensitivity" which is more like an allergic reaction.
You can get blood tests to see if your body is creating antibodies and if there is tissue damage. If you get a biopsy during a colonoscopy they can also tell that way.
As for symptoms - some have diarrhea others have constipation.
My insides have a hard time digesting various foods that are supposed to be "good" such as fruits and vegetables. The worst is veggies with fondue.
Appendicitis, Terminal Ileitis, Crohn's, Celiac Disease, IBS-C, Chronic Constipation, Colonic Inertia, Rectocele, Anismus
Tests: 2 Colonoscopies, 2 CT scans, Sitzmark Test, Anorectal Manometry, Food Allergies, Thyroidism, Pudental Nerve Study, Defacogram, SMART Pill, Electromyogram, Celiac Panel, Small Bowel Study, Gastric Emptying Study - Solids
Pentasa, exercise, diet changes, pro-biotics, mineral oil, vitamins, laxatives, stool softeners, Miralax, Amitiza, anti-depressants , fiber supplements, water enemas, Fleet enemas, suppositories, mineral oil, phenergan, Zofran