Can someone with interstitial cystitis go on a colon cleanse/drink acai berry?

Not going to help: Someone is trying to take advantage of you. "Colon cleanse" is a non-medical scam. And yes, I've heard those crazy ads about "buildup" in the colon too - utter nonsense! Acai is another scam. See a competent urologist or urogynecologist and realize that no matter what you do, IC symptoms will tend to improve and worsen over time on their own.

Not advised: Colon cleanse/drinks will do nothing for IC and quite possibly will aggravate it or cause a flare up for 2 reasons. (1) Acai berry contains substances that can directly irritate lining of the bladder. (2) Mechanics of a colon cleanse induce strong colon contractions which could cause bladder pain.