http://www.medications.com/effect/view/21326 I took my first (and only) dose of Omnicef 4 days ago for a sinus infection and have not stopped having tummy problems. The smell or even thought of food makes me want to vomit, I have constant non-stop diarrhea. I feel woozy and sweaty and like I am goin Sat, 19 May 2007 12:22:54 +0000 http://www.medications.com/effect/view/21326?item=154 I experienced the same thing a few years ago. After a chronic sinus infection, I started Omnicef. I now consider myself allergic to it. I had such bad stomach pain and diarrhea that I had to take off work for a week - and the problems continued for abou http://www.medications.com/effect/view/21326?item=154