Good Morning and welcome to Just answer. I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
Is he still eating well? Has he gotten into anything odd?
Sincerely, XXXXX XXXXX
From what you have told me, it does appear that your guy has a mild digestive disturbance. If this is minor and due to something he ate or stress, the best thing to do for now is to fast him for 24 hrs. This will allow the digestive tract to calm down and heal. At the same time, you can give Imodium AD 2 mg caplets at 1/4 caplet given every 8 hrs.
After the fast, feed a meal of boiled chicken ¼ and rice ¾. If this has helped, wean your guy onto the regular meal over 2 day’s period.
If this is not successful, you will have to have your vet examine your cat to determine if there is something else such as a protozoa or infection that is causing this diarrhea.