Small intestinal bacterial overgrowth syndrome and irritable bowel syndrome

Small intestinal bacterial overgrowth syndrome (SIBO) is defined as an increase in the number and/or changes of the type of bacteria in the small intestine. There are similarities of some symptoms between SIBO and irritable bowel syndrome (IBS). SIBO is also frequently found in patients with IBS and we can observe an improvement after the therapy with some kind of antibiotics in persons with IBS. Some researchers created the bacterial overgrowth hypothesis of IBS. According to this hypothesis SIBO is the primary condition and the symptoms of IBS are secondary. This hypothesis would explain many elements of IBS. Opponents of this hypothesis think that IBS is a primary factor and IBS creates good conditions for proliferation of bacteria and lead to bacterial overgrowth. This article presents the hypothesis and results of research about SIBO and IBS. Relations between SIBO and IBS are unclear and further studies are needed.