pooping in the house?

Question
I just took in a stray she is 7months old. I have already taken her to the vet had her checked out, got her shots, and had her fixed. Well I am a stay at home mom so I am here allday normally she doesnt have an accident during the day it is first thing in the morning. But the bad thing about it is I will take her out she will pee and we will stay outside for a very long time like 30 minutes or more but she wont poop. She just pees then goes and plays, just lays down, or wants to go inside. Then shortly after we go  inside i will find an accident. What do I do? I do have two other dogs does that have anything to do with it? They are all house trained and dont bother her when she is trying to go to the bathroom.  I do the whole cheering thing when she pees and I do not spank her when she has an accident. However I do have a 22 month old so I cant have her having accidents every day can you help?

Answer
Thank you for taking in a stray and giving it such good care.  It is too bad you are having trouble.  It may help to make sure she moves around while outside.  The exercise stimulates the body bringing on a bowel movement.  If that doesn't work, keep a close eye on her after she comes back in.  Does she withdraw to a little used room?  Keep any doors closed and use a baby gate to confine her to the same room as you.  Some people even leash the dog to themselves.  If she stops playing or gets up from a nap and starts sniffing around or running in circles, take her out quickly.

If the above doesn't work, get back to me for other measures.