Help - cat pooing in the house

[Stowickthevast]

Background - I've got two 5 year old cats, a male and female brother & sister.

They generally go outside to go to the loo - big garden and a cat flap. Male wanders further than the female. They have a joint litter tray which they hardly ever use. basically never in the summer and maybe once a month in the winter when it's raining.

The last 3 weeks, the male has pooed in the house about 4 times. It seems to be starting in the upstairs bathroom - which was newly done in the summer which may be relevant. He'll go on the bathroom mat in there after churning it up, also in the new bath 🤬 but has also done bits on the stairs, kitchen, door mat and just outside the litter tray. I've got up twice in the last 2 weeks to a literal shit show. I had closed the bathroom door before I went to bed last night but he managed to get in.

Any suggestions? Get a second letter tray?

Additional info - he does seem very stressed about food at the moment. His sister is a bit podgy so we don't leave dry out on vet's instructions. We fed them dry and wet twice a day at set times but we did get a feeder in the summer which dispenses dry and I think that has stressed him out.

Maybe Feliway too?

He’s clearly stressed and is trying to communicate it.

The rule of thumb is one litter tray per cat plus a spare. Far away from where they eat/drink. Feed them as far away from each other as you can also.

Have you changed the litter type recently?

Also you didn’t pay the cat tax OP … we’re waiting.

Thanks @PegDope. They are fed in different rooms and the litter tray is not near their food.
They do still run over to each others bowls as soon as they can though.

We haven't changed the litter type for years.
Can't seem to attach photos or at least can't see them in the preview ....

I'd definitely try a second tray - we have three for one cat, although he does tend to use the same one all the time. Our boy generally will come in to use the litter tray rather than go outside but if yours is used to toileting outdoors might there be something that's bothered him outside? Our previous girl cat used the litter tray once upon a flood, and would even go out in deep snow rather than use the tray - but we could pretty much predict when she would because it tended to be when she had clearly got in a scrap outside and had a big scrape on her nose or similar.