Small Intestinal Bacterial Overgrowth

In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan.


In contrast to the large intestine, the concentration of the bacteria in the small intestine rarely exceeds 1,000 organisms/mL. Gastric acid secretion and intestinal motility limit the overgrowth of bacteria in the small intestine. When these protective mechanisms against excessive bacterial growth fail, small intestinal bacterial overgrowth (SIBO) can manifest. SIBO refers to a condition in which excess bacteria in the small intestine produces intestinal symptoms. Due to its increased awareness and understanding, SIBO is now often considered in most clinician’s differential diagnosis in patients with non-specific gastrointestinal complaints.

Publication types

  • Review