SIBO is a common feature in IBS and in fact may be directly related to the genesis of IBS symptoms. An ERBHAL on a lactulose breath test may indicate SIBO. Antibiotics and elemental diets have been shown to be effective in treating SIBO, but the efficacy of probiotics is untested. A pilot study was undertaken to determine the effect of L. strain Shirota (Yakult(R)) on intestinal fermentation patterns of IBS patients.