Liz Buchanan BVSc MRCVS
You say that the kitten has hair stuck in its butt and is also stuck to the hair - I am unsure whether hair that has been eaten is working its way out of the rectum, or whether there has been diarrhoea and the area is therefore caked up and icky, or something else. It is important not to pull on anything that is poking out of the anus in case it is attached to something inside. Bathing an external area in lukewarm water can often help with sticky poo. However, exposure to plastered poo and continual bathing, wetting and drying, will indeed make the skin in that delicate area very sore. Furthermore, it doesn't treat the cause of any diarrhoea (soft poo) that may be present so, as you suggested, that alone is unlikely to solve the problem. Antibiotic creams, barrier cream and treatment for whatever is making the poo soft in the first place (worms? Bacterial disease? Something more serious?) may be needed. Therefore, we would strongly suggest taking this small one to an animal shelter or vet where they can get kitten the help that it needs.