I would guess similar symptoms as in an NT child. One of mine and one of my friend's children both had near constant yeast infections when they were babies/toddlers. Her's finally outgrew it with them never figuring out why he was getting them, mine was lactose intolerant, and cutting milk out helped a lot. He also got ear tubes that cut out the near constant ear infections and subsequent rounds of antibiotics. A yeast rash will often bleed when rubbed over by wipies. It also burns and "weeps". It has other visual differences, that I'm sure you could Google, but if the kid goes from clean bottom to bleeding rash in a day, it is probably not a regular diaper rash. This is all from experience with babies, but it is the same infection in adults
As far as I know, there are things you can do to ease the pain and suffering, and slow the spread (a little. It can spread very quickly), but especially if the child is in diapers, I don't believe it can be cured without a prescription. Nystatin cream is extremely cheap, and I believe has a very safe track record. I'm really not sure why it isn't over the counter. It's silly to have to pay for a Dr's visit to get a $6 tube of medicine when your child has chronic yeast infection issues (or you as an adult aren't able to use the over-the-counter medicines for yeast infections/jock itch), but that's the system. I did have a fairly cooperative doctor that would give us a prescription with 6 refills at a time, so I didn't have to go in as often, so that helped some.
If they get it in their mouths, for some reason it is then called thrush, even though it is the same infection. That requires a liquid nystatin (Or an older one that stains everything in the vicinity purple called, I think, Venetian Blue) that is safe for oral use. If they are severe droolers and get thrush, they are prone to spreading it to all the places they drool, especially if you have a chubby little one that has the neck creases, or they dribble down to their armpits or behind their ears. Mine wasn't especially prone to thrush, but my friend's very chubby baby was, and he'd end up with the rash all over him really quickly.
Epsom salt baths help. Absolutely immediate diaper changes, including a full diaper area cleaning each time helps (of course try telling that to the baby with a bleeding bottom--not pleasant). Being able to leave them "open air" for a while helps. Yeast loves dark moist areas, so keeping dry and getting light helps get rid of it. Yogurt with active cultures can help increase good yeast colonies in the gut to help stop sending bad ones down the line. I've never tried this, but the pro-biotic cultures and pills should probably help, and these things can help prevent breaking out in the first place, also, but I'm still pretty sure you need the treatment to get rid of the initial rash, and it will likely come back any time their system gets upset like a stomach virus or round of antibiotics.