My daughter is 3 and fully potty trained. Not even pull ups at night. Just yesterday as she was in the bath, she was complaining that her butt cheeks itched. When I pulled her out of the tub, her butt cheeks were very red, inflamed and welt like bumps. After I dried her off, she seemed fine. Today she just as small red dried out bumps with no more inflamation. Now, I m afraid to give her a bath tonight. I cleaned the bathtub earlier that day with cleanser but always rinse sufficiently and actually took a shower a few hours before her bath. I dont know if it was cleaning agent residue, but if it was, why only her butt cheeks?