FODMAPS are dietary carbohydrates that are osmotic in nature. Means they tend to pull water into the intestine.
In SIBO, FODMAPs are poorly absorbed and are fermented by our intestinal bacteria. The fermented products are then as a food source by bacteria. However, this internal fermentation is not favorable for SIBO patients, as this produces gas and distends intestine with water (25). This is the reason why SIBO patients develop diarrhea, constipation, bloating, gas, and stomach cramps.
The evidences suggest that limiting FODMAP in the diet helps relieve gastrointestinal symptoms in SIBO and IBS patients (26, 27). Therefore, a low-FODMAP diet is recommended to the patients.