Either take him to a veterinary hospital or put him down now.
As good as the local vet is, he's not a specialist and doesn't have the equipment or skills to save this horse. You're just prolonging the inevitable, and the horse is hurting. If you cannot control the pain (and if he's pawing you're not!) you really must act.
I recently lost my daughter's horse due to colic. On necropsy, they discovered a pin head sized hole in his stomach which had leaked into his abdomen, causing peritonitis. No one can even guess how he got it, as there was nothing there to have caused it.
Sometimes, we never find out what was wrong, or what caused it, but still have to do the hard thing for the sake of the horse.
I'm sorry for your (coming) loss.
My vet clinic has 4 different vets. There is an apartment in the clinic and someone stays there 24/7. I live in a small rural area in the US. I think lots of times that's a cop out on here. People want free advice so they play the "vet isn't open" card and don't realize we aren't vets and could give them wrong info. Before I let my cat suffer or die in an emergency situation, I would call the vets at home. Every one has their name listed on their clinic ad in the Yellow Pages and their home number isn't hard to find. There's just really no excuse for not getting to a vet for an emergency.