Had no nausea for the first 3 months, then experienced a spell of stomachaches off and on for a couple of weeks. It was really annoying, but the problem seemed to resolve itself as my diet improved (I was eating poorly for a while before I moved back to my apartment - not sure if this was the sole cause, though. I think the PCS and/or my recent lack of exercise may have played a role, as I've never really had GI problems before).