Hold on a minute here.
If he's eating, he's probably pooping. He may be eating all his poops, and not just the cecal ones. Or if he has a cagemate, the cagemate may be eating them. And if he's eating and drinking and running around and wheeking, it's not likely that he's sick.
How long has it been since you know for sure that he has pooped? Is there another pig in the cage with him? If there is another pig with him, take him out and put him in laundry basket with a light-colored towel and leave him for a couple of hours and see if he poops. You can drape a towel over the top so he feels more secure, and you can put some food in with him.
If he doesn't have another pig with him, then clean his cage and put down fresh bedding. If you're using something like shavings or carefresh, then put a towel over it so the poops won't fall down into the bedding. That way, you can see how much he's actually pooping.
I have no idea what it would cost to take him to a vet in Indiana. I live in Texas. The way you get that information accurately, instead of someone's guess, is to call the vet and ask what they would charge to see him. But I can find no information on the web that suggests these people know anything about guinea pigs. (broken link removed)
