Ask the vet - Cat
My cat is licking its bottom a lot. Should I be concerned?
Vet at FirstVet answers:
If your cat is licking next to its genitalia it is likely to have trouble with its urinary tract, such as an irritated urinary bladder or urethra.
If it is licking itself around its anus it can have problems with its anal glands.
You should seek veterinary care immediately if you find any swellings around your cat’s bottom, if your cat seems to be in pain, or if it has difficulty urinating or defecating.