The purpose of this study is to compare the effects of Infliximab and oral prednisone versus methylprednisolone and oral prednisone in patients with melanoma, lung cancer, or renal cell carcinoma who have immune related Grade 3-4 diarrhea for up to 3 days or persistent Grade 2 diarrhea for more than 5 days after treatment with Yervoy and/or Opdivo