Bacteria normally exists in the intestines. It plays an important role in digestion and overall health. Small intestine bacterial overgrowth (SIBO) is when there is too much bacteria in the small intestine.
The Small Intestines
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SIBO is often caused by a problem with the small intestine. Damage or defects to the intestine may slow the flow of food through the area. The slowed food may encourage the increased growth of bacteria. Problems of the intestine may be caused by:
Any condition that affects how food moves through the intestines may increase the risk of SIBO. Examples include:
Other risk factors include:
SIBO may cause:
Your doctor will ask about your symptoms and medical history. A physical exam will be done.
Tests may include
The goal of treatment is to:
Antibiotics are often used to treat SIBO. Usually treatment is temporary. Some may need to take antibiotics for a longer period.
Proper nutrients can help bring back the balance of bacteria. Steps that may help include:
In some cases, tube feeding is needed with a special formula.
Surgery may be needed for severe SIBO. It may be needed to correct a problem in the small bowel.
If you have any of the conditions that are linked to SIBO, get proper treatment. This may reduce your chance of having a build-up of bacteria in the small bowel.
American Gastroenterological Association
National Institute of Diabetes and Digestive and Kidney Diseases
Canadian Association of Gastroenterology
Canadian Digestive Health Foundation
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Updated May 2016. Accessed October 3, 2017.
Bures J, Cyrany J, Kohoutova D, et al. Small intestinal bacterial overgrowth syndrome. World J Gastroenterol. 2010;16(24):2978–2990.
Lactose and glucose hydrogen breath test. Cleveland Clinic website. Available at: https://my.clevelandclinic.org/health/articles/lactose-and-glucose-hydrogen-breath-test. Accessed October 3, 2017.
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Short bowel syndrome. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T115699/Short-bowel-syndrome . Updated May 6, 2014. Accessed October 3, 2017.
Vanderhoof J, Young R, Murray N, Kaufman SS. Treatment strategies for small bowel bacterial overgrowth in short bowel syndrome. J Pediatr Gastroenterol Nutr. 1998;27(2):155-160.
Last reviewed September 2018 by
EBSCO Medical Review Board
Daus Mahnke, MD
Last Updated: 2/6/2018