In Richard Anderson's book on colon cleansing he states that during a Colon Cleanse heavy metals that have gotten trapped in pockets of mucous, plaque and 'other' matter can become dislodged and cause damage to cells when eliminated. If this is true, I would think that a similar thing can happen with gall stones. If heavy metals can lodge in old fecal matter I would think that it could also get into the liver and land up in stones and possibly cause damage when being expelled.
I am no expert and this is just my opinion but my feeling is that if you are not comfortable with it then don't do it. Trust your instincts.
What herbal chelation program will you be using?
Anna