Flagyl is sometimes prescribed for excessive gas and diarrhea. It is an antibiotics that works well on certain bacteria that accumulates in the GI tract and contributes to the gas and the bloating. 

These bad bacteria flourish when patients consume significant and excessive fiber and carbohydrates (sugars, salad, pasta etc.) The FIRST line of defense against flatulence, bloating, and diarrhea should be eleminating the culprits in the diet.  This point can not be stressed enough.   Adding a daily dose of yogurt may improve symptoms due to yogurts probiotic benefits. To be beneficial, Yogurt should contain live bacteria cultures, not contain artificial sweeteners or have a high sugar content.

Artificial sweetness also area source of the excessive gas and should be avoided.

The Flagyl eliminates and reduces the bad bacteria. Along with a Probiotic and healthy dietary choices Flagyl can help to significantly improved or eliminate those symptoms of gas and diarrhea.

Before Flagyl is prescribed, it is important that the diet is critically examined to make sure that the carbohydrates and the fiber as source of gas and bloating is minimized or eliminated. Excessive use of medications that may be needed for other infections should be avoided.

Chronic diarrhea should be evaluated to rule out GI infection with C. diff bacteria or other bacteria or parasite.

Additional Information on C. Diff (Clostridium Difficile)  and probiotics.