My doctor said this. is it safe?

This guy is a quack. If he truly said these things you need to have him reported to your states medical licensing board. I have no idea why any physician would say such things. If you want to do a colon cleans by all means do so, but it is not going to treat your anxiety or depression. The best thing you can do for these conditions without counseling and medication is get on a regular exercise regiment. That being said counseling and medication are the best modern science and western medicine can offer. Ask about cognitive behavioral therapy. This Doctor is more full of Sh*t than the colon he wants you to cleanse.