Sounds like either yeast or a sort of dermatitis...Either way, I would avoid the cotton balls (I can't use them, the fibers get stuck and irritate me and they are often 'whitened' with bleach...even the cotton pads)
I found the easiest and cheapest thing is still those kleenex...cotton, gauze, bandaides etc just don't do it for me.
I have a lot of fluid discharge from my stoma (it is a little twisted and off kilter so it collects stuff that spurts out at unfortunate moments) so I need something very absorbant that allows it to breath...any waterproof patches or bandaids encourage bacterial growth and cause 'diaper rash' of sorts...
Years back my surgeon gave me a hydrocortisone 1% to use if and when it got red and itchy...I have also found that an antifungal works well too. Both are easy to find at dollar stores in the pharmaceutical department or at Walmart.
If you can, bathe the stoma with mild soapy water and rince well then pat dry and cover with an absorbant cover...use the anti fungal or hydrocort 2-3xs/day.
If you can allow it to air dry a couple of hours a day...when my mom worked in the maternity ward they would put lamps on the episiotomies of the new mothers to 'dry them out' and prevent irritation.
If it works for those tender parts it must work for us.