S.R.
If he still uses a bottle contaminated nipples can cause a yeast infection. It generally starts in the mouth and passes through the digestive system therefor giving the rash to his bottom areas. I have always been told not to use baby powder, but to use corn starch for the rashes because it keeps the wetness from the skin. Just use the yeast infection cream for his bottom and keep nipples or binkies sterilized. I hope this helped.