If ever you suspect colic do not give any feed, unless the vet says its ok, it can make it worse if there's an impaction somewhere, you can give Pepto bismal if you catch it right away,  sometimes that will be enough,  offer some water but don't let him drink 5 gallons at a time, usually they won't drink but a sip but some horses do. drink alot more, a small amount of walking will not hurt him, but don't keep him walking half the night, 10 minutes of walking 20 minutes calm standing rest. move him if he tries to lay down. 
   Praying everything is alright, I lost my old man Shadow 22 in Nov. of 09  to colic/twisted, nothing helped and had I been rich I would have opted for the surgery but 5000, is a lot of money to spend on a surgery that there's no guarantee will even work, especially on a horse who was 22 years old. It was awful having to make that decision to put him down, but he was in terrible pain even under a tranq.  I still cry over my big boy, and I miss him every day. HUgz to you sending prayers Kim