What is the most logical next event?

How to cure a cat of constipation
Monitor if your cat is urinating normally.
A healthy cat may urinate two to three times a day. Straining to urinate because of a bladder infection, bladder stones or a blockage are serious problems and very different than constipation.
Check your cat's litter box to see how much he is urinating every day. Check how much your cat is defecating.