2 1/2 Year Old Starting Peeing and Pooing Inside?

I have a 2 and a half year old male Staffy. He was house trained from a pup and was doing fine, but I'd say for the last 6-8 months on and of he has been weeing in the kitchen on the floor and up the walls. I've tried spraying things, tried him on calmeeze tablets which seemed to work for a while. We went away for a week, 2 weeks ago and left him at home in his own environment with a family friend he knows well and since then he wees and poos in the kitchen.

He gets let out in a morning till 9 sometimes 11, then my dad lets him out at dinner between 1 and 2.30, then again when we get back from work at 5. He has no bladder problems. I'm beside myself and don't no what to do :-( x

By Hayley L