There are a few ways that you can go about looking for a colon hydrotherapist...you can check out the International Association for Colon Hydrotherapy at www.i-act.org for a referral list. Once you have some names, I would call around to health food stores or alt/comp med practitioners...massage therapists, acupunturists, chiroprators....and see if you start hearing the same name repeated. Good colon hydrotherapists usually develop a pretty good reputation and word-of-mouth following.
Prices will probably vary considerably in different areas of the country...I've heard of ranges from $45-100+...be wary of places that push a lot of products or additiional services on you. The colonic session should include the therapist's undivided attention (if desired), and gentle abdominal manipulation to assist you in releasing waste. Some therapists will put their own twist on their service...adding some lymphatic drainage, reflexology, mini-castor oil packs, etc....all well and good, but make sure that they cover the basics first and foremost.
At the very least...make sure that the facility uses purifed water and uses either disposable equipment or autoclaves their stainless steel speculums, and makes reasonable claims regarding the benefits of colon hydrotherapy. Basically, colonics do three things...remove loosened waste material in the large intestine, rehydrate the bowel...which in turn improves the overall hydration status, and improves peristalic function over the course of a series of colonics. If they start talking about curing this-or-that...be careful! Also, don't hesitate to check out the facility before your appointment...it should be clean and free of any odor.
Also, keep in mind that most states do not license colon hydrotherapists, insurance will not cover it in most cases, and certification means very little...as with most governing bodies there are political and financial motivations at play with certification. There are excellent colon hydrotherapists that have learned their craft by apprenticing and do not belong to I-ACT...and there are I-ACT Certified CHTs who are crummy at what they do...that's why I always advise people to ask around!
And always remember...if you don't feel comfortable with the CHT or the facility...do not force yourself to go through the procedure! Honor your gut instincts!!!