Is it dry food? I ask because what this behavior certainluy indicates is
uncomfortable constipation. Wet food would be better for him, simply
because of the moisture content.

Dry food expands in the stomach. Wet food forces the cat to ingest
more water. And, there are just so many other reasons it is better
for your cat.

You can help him by switching to canned food and also by giving him
Laxatone, or Laxaire, molasses-like stuff that comes in a tube and can
be bought at any vet's office. You put a bit on his lips and he will lick
it off. Some cats like it, if yours does not, you might have to kind of
smear it in increments on the side of his mouth so he has to lick it off.
DON'T put it on is paw as some cats will just leave it there.

For canned foods: anything with real meat as a first ingredient, as
opposed to byproducts, is what I use. This does not have to be SD
or any expensive brand. Some varieties of Fancy Feast have beef,
chicken, or fish as a first ingredient, and very little, if any meal.

Not only will you give your cat more water that will help with his
constipation, but he will get more protein and less grain. My vet
said she thinks the extra protein is why my cat now has such super
shiny fur, no dandruff, and much higher energy levels, healthy eyes
and teeth etc. at age 12.

That he had a turd stuck in his anus.

Not unless your life is exceptionally boring.

-L.