Behavioral issue- pooping

Question
I adopted a Jack Russell/Smooth Fox Terrier from the Humane Society in January, named Andy. He is about a year and a half old.  I have 6 dogs at this time.  Two are 14 and will be leaving us soon, 2 are puppies sharing a crate.  All my dogs are inside dogs.  The adults are on Nutro Max small bites.  
Andy seems to be fully housebroken, except.  When we leave him free in the house when we are gone, he poops.  There is almost never any urine accidents.  We let him out at least 3 times before we leave for about 15 minutes a time.  Even if he does go before we leave, when we get back he has pooped in the house.  I had him checked by the vet and there is no medical reason for the accidents.  He never goes in the house when we are home, or overnight.  Just when we leave the home for more than an hour.  He is a wonderful dog  but the pooping is trying us.  We have put him in a crate during the day and he was fine. I have never had to crate a dog for housebreaking before. But how do we ween him from the crate to being loose?  I have a 2 year old Corgi that tries playing with my old guys because he is bored without his Andy to play with.  My 3 and 4 month old pups have a less chance of going in the home, but they chew, therefore the crate.

Answer
It's normal for 3-4 month old puppies to chew. Heck, puppies of ALL ages chew! *laugh*  It sounds like Andy may have a touch of separation anxiety, though. I think that may be why he's pooping in the house when you leave - anxiety. There's nothing wrong with crating him, if he feels comfortable enough in there so that he doesn't poop. What you could try, though, if you want to eventually have him loose in the house all the time, is to gradually increase his space, rather than giving him the full run of the house, or even one whole room, all at once. You can do this by increasing the size of crate you put him in, and/or using an X-pen that you can gradually make larger as he's comfortable, until he's able to stay blocked off in one room. After several weeks of that, you can try giving him the house again.