At the begining of the year I started taking Prolab N large, I took it for a month without trouble. I then switched to EAS from Costco, I was fine for about 2 weeks then out of the blue I started getting real bad stomach cramping from it. I took a week off from it then tried again without luck. I just bought some ON gold standard since its better quality and I'm still experiencing some minor discomfort but not as bad as the EAS. What would cause this just to start happening? I'm a little lactose intolerent but you would think the problem would have started right away. I read that isolates are the easiest on the stomach, anyone have any suggestions on a brand? Thanks.