My Cat Runs and Poops at the Same Time.

Maybe it his way of telling you he would like to start being put outside during the day??

You may want to ask your vet because that isn't normal.

Time to call the vet. Cats don't ordinarily do this, and they don't like to do that. Did he stay at the vet because he had a problem with his insides, or did they not check? That's a different environment, and he may not have demonstrated this problem.

My female cat did that for awhile. She was diagnosed with irritable bowel syndome. She was on a course of meds plus probiotics for a few weeks and now eats prescription cat food. Plus I changed the type of litter in her box to all natural pine pellets. Of all those things, I'm not sure which one helped her or if it was a combination of all but she now poops in her litter box again.