Personally, to me, pooping mean nothing. I've seen multiple colicing horses poop, and then have to be put down later anyways. I've been told, by one of the vets, that the twist could be anywhere, and that poop could've been on it's way out anyways.
Recent, as in the last few colics I've dealt with, we were told to let them stand/rest when they wanted to, but as soon as they showed signs of wanting to lay down (after consistently laying down and rolling) to walk them, and rest again. I want to say they said ten minutes of rest for every half hour of walking if I remember correctly.
Last horse we had colic, when the vet went in to feel around, we found out his spleen was enlarged, vet left him with a 50/50 and he made it till morning and had to be put down. Best lesson horse I've ever known.