It's a great gift to yourself, and it does help release toxins, but I've had no problems from that. It's great if your therapist knows that you're fasting and believes in it. Helps focus the treatment.
And GOOD for MOM!!! I'm nearing 27 days now, and my mom keeps hearing from me about how great this is and how many liver stones I've passed, how much weight I've lost, etc. Now she's thinking about doing it herself, but I'm not confident she will be as resolute as your mom.