Plavix and medication

Severe pain in my lower abdomen. So severe I could not stand straight to walk. Went off the medication for two weeks. Decided to try again because I thought it could have been the flu. The same pain came back in my lower abdomen. I started vomiting and had to go to bed. I went to the doctor and had ex-rays of the area. It has been months and the pain is still so severe that I have a hard time eating or using the bathroom. It's kind of like a cramping pain that makes me want to bring my knees up to my chest to stop the pain. It is a constant pain and never goes away. I am always sick since I took that Plavix.

My mother-in-law is on this medication. I don't understand why. She has had a stroke. Can this med. cause this? Why is plavix used anyway?