Metformin is a cause of late-onset chronic diarrhea. Gastrointestinal adverse effects such as abdominal pain, nausea, dyspepsia, anorexia, and diarrhea are common and widely accepted when occurring at the start of metformin therapy. Diarrhea occurring long after the dosage titration period is much less well recognized. Still it does occur. If you are not tolerating Metformin and Sugar is not controlled without it, try decreasing it to 500 mg. If still the problem doesn t go , change to another Suphonyluea like Amaryl[Glimepride]. Metformin is also contraindicated in Chronic Liver Disease a common cause of diarrhea in itself. Since Amaryl is a prescription drug and a potent oral hypoglycemic, keep some sugary things handy if and when you take it. Consult your physician if you want to switch to Amaryl from Diamicron. Hope that helped.