Many, many people, even highly educated medical people confuse the terms IBD and IBS.

  • IBD stands for inflammatory bowel disease
  • IBS stands for irritable bowel syndrome.

IBD and IBS sound alike. They cause some of the same symptoms – chronic abdominal pain, bloating, and diarrhea. The quality of a person’s daily life can be severely reduced by either IBD or IBS.

However, IBD and IBS are very different. IBD can destroy the lining of the intestines – IBS cannot. IBD can cause life-threatening complications – IBS cannot.

The difference between IBD and IBS can be seen during colonoscopy

The type of tissue damage caused by IBD is visible inside. See images below for tissue changes observed in Crohn’s disease.

Images and caption courtesy of: Jung S. Differential diagnosis of inflammatory bowel disease: What is the role of colonoscopy? Clinical Endoscopy 2012;45:254-262.                         © Copyright Policy – open-access           License

Figure 1: Chronographic alteration in endoscopic findings of typical Crohn’s disease. A 37-year-old female had colonoscopy with complaints of diarrhea. At initial diagnosis, multiple aphthous erosion and linear ulcer with normal surrounding mucosa were noted (A, B). She was diagnosed as Crohn’s disease. After 2 years, colonoscopy revealed the ulcers were deeper with typical cobblestone appearance caused by numerous, confluent ulcerations (C, D). She had been treated with combination of steroid and immunosuppressants. Five months after the treatment, ulcers were healed with fibrotic change (E, F) with resolution of symptoms, and complete remission was achieved. Four years after the initial diagnosis, symptoms were exacerbated and follow-up colonoscopy showed deep ulcers with recurrent cobble stone appearance (G, H) that biologic agent was initiated. Even though the ulcerative lesions in the mucosa improved, stenosis followed, eventually leading to balloon dilation (I, J).
Tissue appears as normal tissue in IBS…
Normal colon tissue
Normal colon tissue
People ask me if the diet I use for IBD helps with IBS.

The answer is that I do not know. I have specialized in IBD, and I have no similar experience with IBS.

That said, I could imagine a pathway by which fiber could have a profound effect on IBS.

  1. IBS is thought to be influenced by the brain-gut axis.1
  2. Gut microbiota influence the brain-gut axis2
  3. Fiber influences gut microbiota3
A model showing my educated guess as to the pathway by which dietary fiber could affect the symptoms of IBS
A model showing my educated guess as to the pathway by which dietary fiber could affect the symptoms of IBS



For a lengthy discussion of IBS offered by The Crohn’s and Colitis Foundation of America, click here.



  1. Fichna J, Storr MA. Brain-gut interactions in IBS. Front Pharmacol 2012;3:906.
  2. Nature Reviews Gastroenterology and Hepatology 6, 306-314 (May 2009) | doi:10.1038/nrgastro.2009.35
  3. Adamberg K, Tomson K, Talve T, et al. Levan Enhances Associated Growth of Bacteroides, Escherichia, Streptococcus and Faecalibacterium in Fecal Microbiota. PloS one 2015;10:e0144042.