Hello there, From what you have described it appears that your bouts of diarrhea was attributed to Metformin. Usually Metformin can cause diarrhea but this diarrhea subsides in a week s time. Only if it does not stop in a week s time and if no other cause for diarrhea is seen then I stop metformin in my practice. Invokana although a good drug I understand that it is expensive. It would have helped to know clearly a few things before I could give my opinion like: 1)what exact medicines are you on and their doses. 2) Has your Metformin been stopped and after stopping has your diarrhea reduced? 3)Why was byetta and januvia changed? Based on present information I can say your sugars are very much in control. If I were your treating diabetologist I would have first confirmed the cause of diarrhea. Sometimes Neuropathy can cause diarrhea also. I would have tried Metformin and Sitagliptin combination for a month to see if sugars remained controlled as they are now. If Metformin is the culprit for diarrhea then using Sitagliptin (Januvia) and a sulfonylurea like Glimepiride could also be tried. Do discuss these options with your diabetologist and am sure your doctor will do the necessary changes. Check blood sugars at different times of the day, fasting, 2 hours after food, before meals. Continue diet changes and exercise in your daily routine. Hope this helps. Take care.