How Can Diarrhea And Vomiting Be Treated?

I have had intestinal issues for 2 weeks. It came on suddenly. Diarrhea, nausea and vomiting. My Dr. put me on 2 different antibiotics and a nausea medication. After 5 days and losing 12 pounds, the diarrhea stopped and then it was constipation. I had to dig it out to relieve the discomfort. The stool was hard, ping pong ball sized and black. I eventually took Dulcolax to hopefully relieve my pain. I had explosive, painful diarrhea, vomiting and passed out for a few minutes. I am still nauseas and taking the pills for that. Whatever I eat doesn t stay in long and results in more diarrhea. There is blood but not sure what it s from.