1. Irritable Bowel Syndrome (IBS) Slideshow Pictures
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3. Diverticulitis (Diverticulosis) Slideshow Pictures

Medical Author:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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Medical Editor:

Bhupinder Anand, MD

In this Article

• What is small intestinal bacterial overgrowth (SIBO)?
• What causes small intestinal bacterial overgrowth?
• What are the small intestinal bacterial overgrowth symptoms?
• What is the normal relationship between bacteria and the small intestine?
• What conditions cause increased production of gas?
• How does small intestinal bacterial overgrowth cause symptoms?
• How is small intestinal bacterial overgrowth diagnosed?
• Is there a relationship between small intestinal bacterial overgrowth and irritable bowel syndrome?
• How is small intestinal bacterial overgrowth treated?
• What's new in small intestinal bacterial overgrowth?
• Small Intestinal Bacterial Overgrowth (SIBO) At A Glance
• Patient Comments: Small Intestinal Bacterial Overgrowth - Symptoms
• Patient Comments: Small Intestinal Bacterial Overgrowth - Causes
• Find a local Gastroenterologist in your town
• Small Intestinal Bacterial Overgrowth Index

One of the major impediments to understanding the role of SIBO in causing disease is the lack of a good test for diagnosis. In the last few years, a new technique for studying intestinal bacteria has been developed that is promising. Bacterial DNA is extracted from samples of stool and then analyzed. The DNA analysis can determine the types of bacteria present as well as their numbers. Perhaps this new technique will be useful in clarifying the importance of SIBO.

• SIBO is a condition in which colonic-type bacteria (resembling bacteria normally found in the colon) proliferate in large numbers in the small intestine.
• SIBO may be caused by dysfunction of intestinal nerves or muscles, intestinal obstruction, or the presence of a blind loop.
• The symptoms of SIBO are abdominal bloating or distension, gas, diarrhea, and abdominal pain. In advanced cases, there may be vitamin and mineral deficiencies and weight loss.
• SIBO is diagnosed by culturing intestinal fluid or with hydrogen breath testing.
• SIBO may be the cause of symptoms in at least some patients with irritable bowel syndrome.
• SIBO is treated with antibiotics, probiotics, or a combination of both.

REFERENCE: MedscapeReference.com. Bacterial Overgrowth Syndrome.

Previous contributing author, Dennis Lee, MD