I've had this morning quite an upset stomach and have been on metformin now for three weeks, increasing my dose over that time period. I haven't had much stomach issues - just twice - and I'm wondering if anyone else has found that certain foods don't agree with them when they are on metformin? I've been wondering this as both times I think I had eaten an omelette or eggs of some description. I read on line of one person who had a similar reaction but they said they thought it was egg yolks and that egg whites didn't give them this issue.