Microbioloby case study question: Gram-positive, endospore-forming bacillius

B. Douglas is admitted to the hospital to receive IV antibiotics for treatment of folliculitis.  He began a second round of antibiotics a few days ago, this time ampicillin. Doug has had diarrhea, abdominal cramps and fever.  Blood tests reveal high WBC counts.  Stool samples show patches of colonic epithelium.  The infectious agent is found to be a Gram positive, endospore-forming bacillus, producing toxins A and B.

4.  What is causing Doug's infection?  Explain your conclusion.
5.  What is this disease called, as evidenced by the epithelial tissues found?
6.  What treatment would you prescribe to cure his current problem and why?

I was thinking Colostrum Difficilium but it doesn't fit in the Bacillus genus. Then I though maybe Bacillus Cereus, I need help. Can anyone help me out?