The detox stuff is pseudoscience. We have organs, the liver and kidneys, that take out toxic materials from our bodies. If they aren't doing that, we die. Whenever you see talk about some miracle substance that "removes toxins" (notice they never specify which toxins these supposedly are), you can be pretty sure that it's mumbo jumbo. Adjusting to a new food or combination of bacteria could be a problem. So can allergies to the yeasts. If you're brewing it yourself, there is also a possibility that some less-friendly organism has gotten into the mix.
People can react to kombucha, yeasts etc. in different ways. i cant drink cheap beer because compounds made by the yeasts from sugar give me migraines. A friend of mine drank kombucha for years, now he can't - he gets sick to his stomach within five minutes of drinking it.
What I would do is start fresh with a scoby from a good source or make your own from live kombucha, and see if you still have the problem.