Like "When I first started Metformin I had diareha really bad as well but as I kept taking it I realized that it happened worse depending on what I ate. I have now learned that the diareha tend to happen when there is too much sugar in my system. I discovered this the other night actually when I cheated and ate a brownie. I had been fine for two weeks without diareha, i ate the brownie and the whole next day was spent running to the bathroom. Since then I've not eaten much real sugar at all save for what it in the fruit I eat and the diareha is gone again. I kind of think metformin might just be a harsh mistress that punishes us when we've been cheating. I can't prove it though. "