adult dogs pooping habits

Question
Me &my boyfriend just got this dog. shes an adult one year old. and the people we got her from you just can tell she was abused. shes scared about every movement and wont take table scraps like she was scared not to at some time of her life. Well she also has this problem being alone, she poops everytime she is alone . i accidently locked her in my room for maybe ten minutes and she poops on the floor. Then when my boyfriend is showing her saying bad dog she poops at that excat moment. Then the other day, we dont leave her alone in the house so i was going to take her with me, i go into the gas station for not even 5 mins and she pooped all over my truck. i dont know what to do. We just leave her outside all day when we arent home and when the weather changes thats not going to work. i need some help b/c we really dont want to get rid of her.

Answer
I am not sure what is happening in some cases.  I have had very little such experience with my own dogs.  I think much of it has to do with stress.  Easily to believe if the dog was abused.  Shepherds may be slower to shake off such problems too.  

One thing you might try is the same confidence building exercises I suggest for submissive wetting. Start with obedience training.  The key to most behavior problems is approaching things using the dog's natural instincts.  Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog.  Life is much easier if the 2 legged pack members outrank the 4 legged ones.  You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/  As you praise the dog for following your commands, it will build its confidence.  

Play tug of war with the dog and lose.  However at the end of the game, take the rope or toy and put it up, less the dog becomes confused about who is top dog.  Ropes from the pets' store quickly turn to hazardous shreds.   Ones I made  lasted much better.   Go to a hardware or home center that sells rope by the foot.  Buy 2' of 3/4" poly rope. Melt the ends, and tie  knots in it.   Get them as tight as possible, put it in a vise and pound it with a hammer.  Watch carefully, and be ready to discard when it comes apart.

Finally, make sure it has a den to live in.  If you are not using a crate, buy one.  The dog may be happier in its den than loose in the house.  It relaxes, it feels safe in its den.  It rests, the body slows down reducing the need for water and relieving its self.  Dogs that have been crated all along do very well.  Many of them will rest in their crates even when the door is open.  I think the plastic ones give the dog more of a safe, enclosed den feeling.  Metal ones can be put in a corner or covered with something the dog can't pull in and chew.  Select a crate just big enough for the full grown dog to stretch out in.

A dog that has not been crated since it was little, may take some work.
Start out just putting its toys and treats in the crate.  Praise it for going
in.  Feed it in the crate.  This is also an easy way to maintain order at
feeding time for more than one dog.

Another thing to do is leave her with a Kong stuffed with peanut butter.  Kongs are a common rubber toy, hollow.  

Table scraps are a bad idea.  Dogs need a complete and balanced diet.  All but the cheapest chows are carefully formulated to give dogs just what they need.