Bacterial Overgrowth

Small intestinal bacterial overgrowth (SIBO) was originally described as a cause of maldigestion and malabsorption but has, more recently, been recognized as an important cause of otherwise unexplained diarrhea. The symptoms, signs and laboratory findings associated with this syndrome result from disruption of digestion and absorption by an excess of bacteria normally confined to the colon. Any disease process or intervention that impairs acid secretion or small intestinal motility or distorts anatomy in a manner that leads to the development of blind loops, stagnation of intestinal contents or re-circulation of colonic contents into the small intestine may result in SIBO. Pending the application of molecular microbiological methods, there is a lack of a gold standard for the diagnosis of SIBO for each of the commonly used methods; culture of aspirates from the duodenum or jejunum, breath tests and therapeutic trials of antibiotics having their limitations. Therapy remains, for the most part, empirical and is based on the correction, where possible, of any underlying cause, attention to nutritional deficiencies that have resulted and the use of antibiotics.