Small bowel bacterial overgrowth


Definition

Small bowel bacterial overgrowth is a condition in which very large numbers of bacteria grow in the small intestine.

Alternative Names

Overgrowth - intestinal bacteria; Bacterial overgrowth - intestine; Small intestinal bacterial overgrowth; SIBO

Causes

This EM Should be displayed at the top of the article section "Causes"

Most of the time, the small intestine does not have a high number of bacteria. Excess bacteria in the small intestine may use up the nutrients needed by the body. As a result, a person may become malnourished.

The breakdown of nutrients by the excess bacteria can also damage the lining of the small intestine. This can make it even harder for the body to absorb nutrients.

Conditions that can lead to overgrowth of bacteria in the small intestine include:

Symptoms

The most common symptoms are:

Other symptoms may include:

Exams and Tests

Your health care provider will perform a physical exam and ask about your medical history. Tests may include:

Treatment

The goal is to treat the cause of the bacterial overgrowth. Treatment most often consists of antibiotics. In some cases, drugs that speed intestinal movement (motility-speeding drugs) may be used. A low carbohydrate diet can be helpful.

Treatment also involves getting enough fluids and nutrition. A person who is dehydrated may need intravenous (IV) fluids in a hospital. A person who is malnourished may also need nutrition given through a vein (total parenteral nutrition -- TPN).

Possible Complications

Severe cases lead to malnutrition. Other possible complications include:

References

Manolakis CS, Rutland TJ, Di Palma JA. Small intestinal bacterial overgrowth. In: McNalley PR, ed. GI/Liver Secrets Plus. 5th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 44.

Quigley EMM. Small intestinal bacterial overgrowth. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 10th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 105.

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.