Is My horse colicing?

My horse is 2 years old and he is a Appaloosa Stallion. He has been very gy tonight and acting different. He has coliced before but it was more seriouse. It was around 6:00 pm tonight that he was acting very different but he was still eating and acting like he usually does. I am just concerned because he has coliced before. I really don't want to call a vet. Does anyone have any ideas of what I should do?