After thinking about this, I would be surprised that in a city like Columbus there wasn't one or more professionally practicing colon hydrotherapists.
I suggest that you call some local health food stores and ask if they can recommend anyone. Also try chiropractors or other practitioners who portray themselves as offering holistic, alternative, or complementary therapies.
Massage therapists can also sometimes refer you to someone nearby.
Often, these type services are offerred by referral only.