Small bowel bacterial overgrowth is a condition in which there are too many bacteria in the small intestine. Normally, there are far fewer bacteria in the small intestine than there are in the large intestine. Over time, small bacterial overgrowth can cause malnutrition, as the small intestine is unable to properly absorb the nutrients the body needs.
Small bowel bacterial overgrowth occurs as a result of abnormal motility (movements of the digestive system and contents within it) in the small intestine. This causes the bacteria in the small intestine to multiply.
The symptoms of small bacterial overgrowth include bloating, pain and diarrhea. These symptoms usually occur after eating. Bacteria in the small intestine consume the food eaten and create gasses, which cause bloating and diarrhea.