You say that stools are normal "outside the crate." If that means "outside of the issue of soiling in the crate, all stools are normal," that's one thing. If they are soft/loose when in the crate or left alone, that's a strong indicator of a very anxious dog.
In addition to dealing with anxiety and confusion, which may be a big part of this problem, feeding schedules are a good place to look. If you're free-feeding, STOP and get Precious on a schedule. No more than twice a day and most healthy dogs do fine on one meal and maybe a snack later in the day. Random input creates random output and that's very tough to manage in a situation like this. Feeding a more compact food can also help. This can range from a higher quality, grain free kibble which will produce less bulk in the GI tract and less "ammo" in the crate, all the way to straight raw meat, or anywhere in the middle.
The "spite" issue is not one I buy into... dogs become confused, stressed, anxious, and they act out. It's not the same mental process as what we think of as spite, and they don't have the same feelings about poop that you do. They will mark with their poop, so if they are anxious about their place in the world, that's a behavior that can occur.
But as Doug says, it's really a semantics thing. Dogs will do things we don't like when upset, and making them not feel that way will stop the behavior. Whether Precious is "marking' or "telling you she's mad" or "pooping because she's stressed," the solutions will all be similar, in fact.
Nothing In Life Is Free is a PITA but it is an awesome way to make a dog feel calmer, less anxious, and less in charge. That's because being in charge makes dogs anxious. Many times what we view as "loving" a dog is what they view as "making me be in charge of the whole world!" and that creates a lot of problems. Sometimes that's obvious in other ways... a dog that tries to boss other dogs or people... and sometimes it's a little less obvious due to the dynamics in the household.
Pheremones, supplements (L-tryptophan, sam-e, valerian are a few) aromatherapy (lavender has a calming effect on dogs) as well as something to do (a chew toy she likes) can all help with an anxious dog. Beyond that there are prescription meds that can reduce anxiety. How you leave the dog and how you come back can be very important in SA situations, also. There's a lot to learn. You may just want to google around a bit (in addition to the article that Doug posted) and learn what you can and see how that fits with what you've seen.
susan
Fuzzy Wuzzy was a wabbit, Fuzzy Wuzzy had a dandelion habit! RIP little Wuz... don't go far.
