So, as title, last night I noticed poo sticking out of my cat's bum. DH held him while I went to wipe it off but it was solid, like a doweling rod, so I had to pull it out. 
Google tells me it's dehydration but he has wet food three times a day (small tins) and there is always water down.
Does he need to see a vet or should I just keep an eye on him and if so what am I looking for?
He's about 11 but we've only had him two years and I don't know his history.