My son is very prone to a sore bottom when wearing his nappies - we've tried all sorts (changing nappy types, creams etc) but one of the things that works is letting him play for long periods without a nappy. However, he has started obsessively grabbing and playing with his privates, sometimes so hard he gets scratches that bleed and since I don't know how to stop him I've had to stop letting him play without the nappy and his bottom is getting worse. Does anyone have any ideas how to stop this behaviour?