I have been a long time user of whey protein supplements. Recently I had stomach infection which lasted for 1 week. During this time I did not take any supplements.After the infection got cured I resumed taking whey. Now the problem is whenever I have whey in the evening around 8 pm (after workout) I have smelly gas around 11 am the next day and loose motion at around 1 pm. I switched the protein brand but still the problem persists.

It doesn't seem to matter if I take whey with water or milk. I am lactose tolerant. Can anyone please tell me what is wrong with my stomach? And why does it happen at noon only?