Small intestinal bacterial overgrowth (SIBO) is a condition in which there is an abnormal increase in the overall bacterial population in the small intestine, particularly types of bacteria not commonly found in that part of the digestive tract. This condition is sometimes called blind loop syndrome. SIBO commonly results when a circumstance, such as surgery or disease, slows the passage of food and waste products in the digestive tract, creating a breeding ground for bacteria. SIBO can cause a range of symptoms, including loss of appetite, abdominal pain, nausea, bloating, an uncomfortable feeling of fullness after eating, diarrhea, unintentional weight loss, and malnutrition.

SIBO can be caused by a variety of factors, including anatomical problems, medical conditions such as Crohns disease, radiation enteritis, scleroderma, celiac disease, diabetes, or other conditions that can slow movement (motility) of food and waste products through the small intestine. Medicines such as narcotics can also cause SIBO. Alcohol abuse can damage the microbiome, leading to dysbiosis, damage to the intestinal walls, and inflammation.

Treatment options for SIBO include antibiotics, which are the most common treatment. If SIBO is caused by an anatomical problem, surgery may be needed to correct it. Diets cannot cure SIBO, but they can lessen the symptoms. A popular option is the low FODMAP diet, which limits the intake of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols.

In summary, SIBO is a condition in which there is an abnormal increase in the overall bacterial population in the small intestine, which can cause a range of symptoms. It can be caused by a variety of factors, including anatomical problems, medical conditions, and medicines. Treatment options include antibiotics and diets that can lessen the symptoms.