I don't know about the stomach issues, I might be wrong, but glyco shouldn't cause stomach aches.
I take glyco in the morning around 6 am then again at around 12:00 and then just before bed. Also I fast the whole day and only eat around 9:00 pm. It works wonders on an empty stomach.
Thats right, its great on an empty stomach since it cuts down on acid production. But I wonder if that is why you shouldn't have a full stomach when you take it.