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Symptoms and Signs of IBD vs. IBS: Differences between Symptoms, Causes, and Treatments

Doctor's Notes on IBD vs. IBS: Differences between Symptoms, Causes, and Treatments

Inflammatory bowel disease (IBD) is chronic inflammation of any part of the digestive tract (from mouth to anus) and has two main types, ulcerative colitis and Crohn's disease. Irritable bowel syndrome (IBS) is considered a chronic functional disorder of the GI tract because in people with the disease, the GI tract acts abnormally, but there is no structural damage from a specific disease. Signs and symptoms unique to IBD include diarrhea that may be bloody, rectal bleeding, weight loss, joint pains, skin problems, fever and/or severe or chronic abdominal pain. Signs and symptoms unique to IBS include non-bloody diarrhea, abdominal discomfort (not severe or chronic), gas, bloating, changes in bowel frequency and stool appearance, pain or discomfort that improves after a bowel movement, constipation, feeling unable to empty bowels, mucus in stools.

Possible causes for IBD include autoimmune response or immune over-reaction and/or genetics. Possible causes of IBS include brain-gut signal problems, GI motility problems, high GI pain sensitivity, altered levels of neurotransmitters, food sensitivities, small intestinal bacterial overgrowth, GI bacterial infection and/or genetics.

Medical Author:
Medically Reviewed on 3/21/2019


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.