Hi, I Have Chronic Diahrrea And Abdominal Bloating. I've Had

Hi, I have chronic diahrrea and abdominal bloating. I've had and upper and lower GI and am told everything is fine. I was told I have IBS. Was prescribed Viberzi, took one dose and had a seizure. My stomach is so distended I look 4 months pregnant. I know this isn't normal but my doc keeps telling me it's just IBS. I don't eat and I feel like I'm going to throw up; I do eat and I feel sick and often get diarreah soon after. I'm concerned