I had this problem with my half MC/half Ragdoll who we got from rescue just over a year ago. His poo was absolutely stinky and slightly loose. Because he's long-haired he kept getting poo stuck to his fur!!
He doesn't really eat wet food at all in spite of my attempts to persuade him but he drinks a lot from his water fountain (he is slurping noisily as I type!)
He gets the little Purina tins or Sheba trays but he only licks them a little. I changed him onto Scrumbles dry food (Tesco/Sainsburys/PetsatHome) and it's been a game-changer! I also stopped giving him Dreamies and instead he gets Scrumbles or Mr Pickle treats.
The other thing we did was put more litter in his tray. My boy is indoor too.