Metformin is available in both regular and extended release pills. One of the more common side-effects of regular release Metformin for some is persistent diarrhea. The extended release (ER) version can help reduce the diarrhea occurrences a bunch.
As to sugar, it is pretty much unavoidable as it's in practically everything to some extent, especially processed foods. Read the labels and what you want to watch for besides carbs is, "added sugars", which is something you can avoid.
