I actually had some mild-to-moderate nausea kick in after a few months, in part because I wasn't at home for about a month and my diet wasn't that great during that time. Probably a combination of diet + vulnerability from PCS.

I drank a lot of Traditional Medicinals "Ginger Aid" tea, improved my diet, and started on "Bio-K" probiotic yogurt on the advice of my naturopath (I'm still taking it - it's not cheap, but it seems to be helpful).

The nausea/upset stomach gradually went away after about a month - it's pretty much a non-issue at this point.