Lithium can cause GI upset when first starting , Its always best to take it with food ,Worst case your Pdoc can give you a script for anti nausea meds.. It does usually go away after a couple weeks for "most people"

I no longer take Lithium. I'm only on Lamictal and will be going off that soon. I'm going med free for a variety of reasons.

I hope your side effects lessen and you get the benefits of lithium.

Licketsplit is correct regarding salt intake and the effect on lithium levels.