The sessionms are about 45 min. each. Diana, the first reference I gave you may give you another 5 or 10 min, if needed, the others won't.
How many sessions probably depends on each individual. See how you feel after a few... I do my colonics mainly after a liver flush. Have had 5 colonics within a seven month period. Used to have a lot of gas, gurgling, churning, discomfort, "irritable bowel syndrom" is what one doctor called it, for lack of knowing what was really wrong. Now it's peaceful and quiet down there....