IBS is the most common gastrointestinal diagnosis. The symptoms of irritable bowel syndrome are similar to those of small intestinal bacterial overgrowth. A study by Dr Mark Pimentel and colleagues  set out to see whether overgrowth is associated with irritable bowel syndrome and whether treatment of overgrowth reduces patient's intestinal complaints.

They found that after treatment with antibiotics, half of IBS sufferers from both IBS and overgrowth, the IBS symptoms disappeared. The overgrowth test can be done in doctors' surgeries.