constant nausea: IBS or something else?

Hello, my name is Gigi. I just found this site and want to offer everyone out there my condolences. It is difficult to struggle with your health on a day to day basis and hopefully this will all be a distant memory for each and everyone of us soon. I have a question I hope someone can answer for me. I am 23 years old and have been suffering from constant nausea for the past 6 months. This came about very suddenly late one night after I ate beef stew and took a 2 week expired aspine. Although the symptoms have since wavered, I recently noticed that I sometimes feel very nauseous if I have to pass stool. Other symptoms include bloating, burping, strain/pressure in the throat. I have had an upper GI barium test- normal- and a stool test for Giardia- also normal. Doc at the University of Penn seems to think this is either IBS or gastroparesis. Has anyone else experienced nausea as the primary symptom for IBS? BTW, I have tried Tigan, Propulsid, Previcid, Zantac, none of which worked. Currently, I am taking Levbid which has offered some relief but has a few strange side-effects. Ginger tea does work nicely and I purchased some Ginger pills but am scared to mix them with Med. Strangely, Echinacea seemed to help as well, I suspect that is due to its alcohol content which could act as an antibiotic. Thanking everyone in advance, sorry the post is so lengthy. You are all in my prayers. Gigi