When my now 11 y/o was an infant I gave her creamed spinach (yuck) and she had a terrible rash. So bad that it scabbed. My pedi told me to use Domboro(spelling) and it was wonderful. After 1 use it was almost gone. You can find it in the first aid section of any store. Just follow the directions. I also have heard not to give immodium to an infant. I think whatever is giving him the diarrhea needs to work out of his system. I might call my dr. and ask about to roto virus as well. Good Luck!!