Prochlorperazine
"I have IBS along side Colitis and also have had regular pure Chronic Nausea since I was a young teen and I'm 34 now and still have the problems. I pretty much have all the basic nausea meds so when one isn't working I have others I can fall back on. But the 2 that are the most potent are Zofran and Compazine. And out of those 2 the most potent for me is still the generic Compazine, even after all these years of taking it. The only downside is its a fairly old antipsychotic which means it comes with some fairly rough side effects sometimes. There have been a couple times I've gotten the side effect of Dystonic effects with are horrible to go through. So now when I take my Compazine I take it with 50mg of Diphenhydramine (Benadryl)."