my 18 month old staffy keeps going to toilet over night

for the last week, my 18 month old staffy keeps weeing and pooing in the kitchen over night
he goes around the park about 8.30pm and has a wee and poo, then he goes to a patch of grass about 10.00pm and has a wee
every morning for the last week we have woke up to a mess in the kitchen, he has never done this before until now, any ideas

Has anything changed recently? Food, exercise, etc? What's he fed on and how much exercise does he get?

he is on the same food, he goes for an hour walk in the morning off the lead so he runs around, he goes to the park about 2pm before work and then i walk him around the park about 8pm and then take him to a patch of grass for a wee just before bed, he use to be fine and was clean over night accept for the last week

I had the same problem when Blue was about 1. He used to sleep in the kitchen. I ended up just buying him a bed for the bedroom. He now sleeps on the floor next to me and he sleeps until I get up. I treid everything and nothing worked. I even concidered getting a camera and a mic/speaker and staying up so I could correct him when he was in the act because no matter what times I went downstairs I could never catch him in the act. So frustrating

As Mike says, sometimes the age has something to do with it.

Other than that, I wonder if it's either anxiety or a slight tummy bug? Is he ok in himself, still lively & eating/drinking well? Have there been any strange noises in your area recently - building work/road digging etc?

I'm sure there is a reason for the sudden change in his behaviour, I hope you get to the bottom of it soon. Perhaps he is a little under the weather?

maybe worth popping him to the vets for the all clear

He did have an upset tummy for 4 days and went of his food, he seems ok now as he is eating well and fall of enegy. He has never done this indoors untill now but he looks fine in himself