Would my dog avoid pooping if he's been having back pain?

Small chihuahua mix (maybe some min pin or dachshund) was bloated and in pain. Vet's xrays showed major constipation and fullness in stomach. Vet gave enema, we took him home and tried to wait for him to poop. Progressively throughout the night, his hind legs seemed to stop working - he would try to use them but sort of dragged them behind him. The poor thing couldn't even squat when he finally had to poop My question is - would he have been holding in his poop for the past few days if he'd been having back pain? It seems like he may have slipped a disc or something like that (he's with the vet now) but I am trying to find out if the constipation or the potential spinal problems came first. Any help is greatly appreciated.

Ah love him and the answer is yes he would associate pooing with the back pain, and it hurts a human let alone a poor little dog. I think he had the spinal problem and the nerves relayed to his bowel, I really hope he's a lot better now and you sound stressed out, it's terrible to watch a little creature in pain. Try to feed him some fish to keep his bowels loose as he can't afford to get constipated, the nerves are the control centre of any body animal or human, the brain just directs our movements.