Changing from byetta

I've been using byetta for about 2 1/2 to 3 years, lately my stomach has been upset most of the time, stools real hard and painful when trying to pass. I stopped using byetta last week and those two problems have gone away. Also I am sleeping much better, able to get to sleep easier and not waking up as much during the night. So I feel I should change to something else.

I am currently using Glyburide and have used it ever since I was told that I hade diabetes.

After looking online at different drugs, I have come up with two that may work. First is Janumet (metformn +Sitagliptm) and second is Precose (Acarbose).

I am asking if anyone has used either of the two above drug and what the outcome of their usage is. Any downsides to the two drug.