why am i gassy

[vnlsin]

I've taken E about 10 times in the past 2 years, with no problems, but the
last 3 times I've done it i've developed a problem with flatulence (farting)
while on it, This is rather embarrassing and I'm not sure what the problem
is. The problem goes away when I'm coming down. Could this be
something in the drug, or maybe my muscles contracting? I'm not aware of
anyone else having this problem at all and it's making me think there might
be something wrong.