dog wont stop pooping in the house

Question
my dog is a 3 year old staffy. he is let out numerous times a day to go to the toilet and even when he poo's and wee's outside right before i leave the house he will always poop and wee. even if he is only been left for an hour, i always come back to poop and wee. he has only started doing this for the past 4 months and i am unsure how to stop him doing it as nothing seems to work. i dont understand why he is doing this, its not like he is busting to go to the toilet because he always gets let out and poos and wees before i leave. he has been well trained all his life and aside from moving house, nothing major has happened that would make him do this. iv tried saying things like ''good boy'' when he poops outside and giving him treats when he does but it still does not work. please can you help me as i cannot cope with it much longer.

Answer
Hi Kirsty. First some questions:

How long ago did you move and did this housetraining trouble start just after you got into your new home?

Does he ever do this when you are at home or is it just when you're away?

Have you talked with your vet to be sure there's not something medically going on with him?  Sudden onset of behavioral changes are often medical issues.  That should be ruled out ASAP.

Does he get anxious when you leave (whining, barking, destroying things while you're gone)?

Here are some suggestions to start right away:

Check your dog food bag.  Be sure that you are feeding a high quality dry kibble that contains no corn or corn products or by-products of any kind.  

If you free-feed (leave the food bowl down all day), stop.  Feed twice daily, putting his bowl down for 15 minutes, picking up whatever he doesn't eat.  If you can control intake, you should be able to better manage output.  Be sure he's not getting too much food.  Read the bag to ascertain how much he should be getting in each meal.

Keep a log of when he eliminates so you can get an idea of how long it takes the food to pass through his system.  You must go outside with him so you can be certain he's done his business and you can track it.

Go back to Puppy Housetraining 101.  If you're leaving him alone, crate him.  Most dogs won't soil their sleeping areas.  Be sure that he's emptied his bladder before you leave.  Take him on a walk so he has plenty of opportunities to do this.

I have a suspicion that this is stress-related and associated with the move to a new home. I'll wait to hear back from you on answers to my questions and I can provide more suggestions based on that.