Nothing substitutes for a conversation with your own surgeon, and I would recommend that you contact them to discuss the matter further. They may have some questions for you, as the term "colonic" is not specific. The term can cover a variety of treatments from innocuous home health kits to visits to hydrotherapy clinics that may employ high volume colon cleansers with substances such as herbs or even coffee. I think I would be reluctant to permit a patient under my care to undergo some of these procedures as they could risk dehydration, electrolyte balance, or even bacteremia (bacteria entering the blood stream) that could increase risk of infection. Best of luck with your upcoming surgery.