Hi, Shari (Sampy).
The first few weeks of taking Plaquenil, I honestly didn't know how to sort possible reactions from disease symptoms. e.g., I've had IBS for 25+ years, and vrs. symptoms were really BAD at the point of Dx.
So, which was which, flare or medication reaction? Dunno!
If stomach upsets are a common thing for you, maybe you could take a "wait & see" attitude? Even if they aren't, it probably takes awhile to adjust...
Not very helpful!