Regressed potty training

So my 7 month old staffy was completely potty trained at about 2 months and now all of the sudden he's been pooping inside at night. Like 7 different piles! He used to sleep in a dog bed next to ours till he started pooping inside. It's not every night maybe every two days. Anyways now he's been sleeping in his kennel for about two nights and tonight he just pooped inside of it. :/ we stopped giving him food after 7 he went for a walk and pooped and peed before he went in and it still happend? What can I do to stop this?