Is the cleanse you are doing Dr. Schulze 's intestinal cleanse? If so, these symptoms are normal for the first night. Usually it is just all that old gunk getting ready to come out. I would recommend drinking plenty of water and following the instructions to increase your dosage by one pill each night until you are having between 1-3 bowel movements a day. Things can feel pretty icky when there is upheaval of the status quo...you'e had that stuff in your system for years so it is natural that it would do a bit of protesting on its way out. But use your judgement. If you faint or have too much of a rapid heartbeat, discontinue obviously. Let us know how it goes!