tail less stray cat

The mom cat and I think the dad cat both have nubs for tails there are three kittens two with tails and one without a tail at all nothing and it looks like its butthole is swollen any help would be appreciated. My neighbors are taking care of them, food, water and a little bed. I just hate to see any animal suffer so please any advice would help. It doesn't seem to be in any pain though. Ironically out of the three kittens the one without a tail is the nicest.

Cats that are born with no tail or stubby tails actually have a type of inherited congenital defect.  Manx breeders try to control the effects by never breeding 'rumpies' together.  They sometimes don't succeed.  Issues with the bowels is one of the things that can result if the defect is significant.  Is there any way these kittens can get to the vet for checks, vaccinating and spay/neuter?  I know it sounds like they don't belong to anyone.  There are TNR groups that may be able to help you with basic vet care.