OMG! This is so EASY to solve!!! My 2-year-old son got a staph infection in his diaper area. He had to go on majorly strong sulfa antibiotics for 10 days. Yes, little boys do get yeast infections, too. I put him on double the dose of a children's chewable probiotic (upon the advice of his pediatrician) called Primadophilus Kids. He loves them. I gave him one in the morning and one at night. I decided to keep him on them but just the normal once-a-day dosage. Well, after a couple of weeks I quit. Soon thereafter he got another diaper rash! Instead of more antibiotics, I decided to just put him back on the probiotics, and IT WORKED!! The rash cleared up!! So, he has been on them ever since. It has been months, and he has never had one single diaper rash or infection. Try it! You can get them at Mother's Market, Henry's Market or any Whole Foods Store. It has to be kept refrigerated, b/c the cultures are live. Here's a link to the product I use:
http://www.allstarhealth.com/f/natures_way-primadophilus_...
BTW, I also started taking adult-strength probiotics everyday, and I have never felt healthier, even when a cold went through my whole household. I never got it!
Best wishes!