Just leave him be. He is better off in the incubator than out right now. Remember they can go 3 days without food and water. Thier yolk sac gives them everything they need nutritionally for now. Let him stay in the bator and absorb the rest of the yolk. If it is his intestines he will die if you cut them so I would just leave him be in the bator overnight and see how he is tomorrow morning.
