Hi and welcome to HCM. I m Dr. Taimur and I will be addressing your health concerns. I have read your question and understand your concern. The tylenol and aleve are gastroprotective and are very much unlikely to cause abdominal pain and bowel disturbance. But the Zetia may result in such symptoms like you narrated, which may be due to liver injury. If there is liver injury you should be jaundiced and also have muscles aches and pains and low grade fever. To exclude the above causes relevant investigations should be done. So my recommendation to you is to get an appointment with an Internest and get yourself properly examined and investigated. I hope this might be of some help, if you have any query feel free to ask me any time. Thanks. Dr. Taimur