Ridecamp: [RC] ulcers symptoms/endoscopy

I have a gelding that gets what appears to be gas colic every few months. The only hole in my worming program is that I have never wormed specifically for tapeworms. (I will correct that after Old Dominion) He has shown diminished gut sounds at rides. He eats Enduro-event, beet pulp and hay (no alfalfa). He lives on a 75' by 75' dry lot (its sandy here). I used to feed psyllium, but doesn't the beet pulp remove the sand? (Susan?) Do small vets have the equipment to check for ulcers and what is the usual cost? I also wondered about enteroliths, and how to check for them. 

                        Shelly