When do I stimulate a cat's anus?

I don't fully understand the concept. Do I do this after ten minutes of my cat eating? Or is this a remedy exclusively for constipated cats? Clarifications would be appreciated.

Stimulating the anus is generally done with very young kittens that are being hand reared. It's not generally necessary in healthy adults or older (fully weaned) kittens. When it is done, I believe the technique is to use a warm damp washcloth and mimic the licking motions that a mother cat would use in order to help the kitten poop. It is done immediately after feeding.

Columbine is correct. This is done primarily for orphan kittens who have no mom to do it for them. Non-weaned kittens cannot go on their own without stimulation. Some tap with the fore finger as cloth can sometimes cause irritation over time.