Small intestinal bacterial overgrowth (SIBO) is a condition where 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. The excess bacteria often cause diarrhea and may cause weight loss and malnutrition.

Symptoms of SIBO often include loss of appetite, abdominal pain, nausea, bloating, an uncomfortable feeling of fullness after eating, diarrhea, unintentional weight loss, and malnutrition. SIBO can be diagnosed through tests to check for bacterial overgrowth in the small intestine, poor fat absorption, or other problems. Treatment for SIBO focuses on correcting nutritional deficiencies and eliminating bacterial overgrowth, which is often done through antibiotic therapy. Nutritional supplements may also be necessary to treat malnutrition.

Dietary changes may also be helpful in managing SIBO. A low-carb diet and probiotics may help manage bacterial overgrowth, and a short-term elimination diet may be recommended to induce remission of SIBO. However, it is important to consult with a doctor or gastroenterologist before making any dietary changes.