I definitely would suggest the probiotics as well....
The other....Canesten cream which can be bought otc should help.
It will soothe and help the infection.
What soap is used to clean him? Maybe something like Cetaphil will be more gentle than soap.
What laundry soap do you use and do you use a fabric dryer sheet or liquid?
Using a bit of vinegar in the laundry wash cycle can help as well.
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