I have a 2.5 year old small mixed female dog. She is housetrained in the sense that she will only urinate outside. She will not poop outside. It doesn't matter how long she is out, she will not poop. Just will not. She waits until we come in and she goes to the same spot and goes. My husband and I have tried putting her in her crate after coming back in from urinating outside, but she holds it and when we take her back out later, she still just urinates - no poop. She is not constipated or anything like that.
Im just wondering if anybody has any tips on how to break her of this. She has done this since she was a puppy, and we always thought that if we were consistent she would eventually learn.
We have a male black lab that stays in the house also, and we've never had a problem with him.
Any suggestions?

I think some dogs are just creatures of habit and for some reason she has it in her mind she is suppose to do it this way. My huskie/lab was the same way. She would pee outside and then poop in the furnace room. Although she would go outside as well, but often waited until she came back in. Since it was a room that was never really used I put paper down and just let her go in there.
You said she goes in one spot all the time. If it is an out of the way spot then I would start by putting paper down until I could come up with a way to get her to go outside.

Try re-training her, on the spot she excreats in put news paper down, when she looks like she is heading for that direction pick her up and put her outside but don't grab her as she might not be prepaired to be lifted so fast.

Hope it works, I'm no expert but yea

We've tried that and it doesn't work. She knows she's not supposed to go in the house, because she will sulk and go hide after she does it. But we can never catch her in the act. She absolutely will not go in front of us. Ive thought that she is "modest" and that is why she won't go outside (because we HAVE to keep her on a leash.)
I even work at a vet clinic and they're all baffled just the same.

We have a small breed shih tzu and he was tough to train. Here's the deal, you have to find out what works for her. A lot of people will offer suggestion including me and it will have to be whatever ends up working for your dog. I know that we tried with our dog to put papers down and he didn't like the papers so he went next to the paper. Never on the paper. We tried the pads, nope, our problem was that he was liter trained in the beginning and we tried to switch. We ended up getting our dog an indoor potty system that seemed to do it for him. However, yours is a different problem. Is it possible to leave him outside until he has finished? Train him to understand that he has to do that before being let in. Do you walk him regularly? If son longer slower walks could help.

Yes, we take a walk regularly, and they have a fenced in area for them to play in. Even when she's in the fence, she will not poop there.
Im beginning to realize that this is just what she does and accept it, but I just wanted to know what other people did in a similar situation.
Thanks!