i think there is no difference of the nurse's role if you work in endoscopy. universally, your role is to keep the patient's safety. so in endoscopy, i would say that you have to monitor patient's vital signs and report for any unusualities, provide patient's comfort, do ur documentation, and maintain patient's dignity esp if patient is undergoing flexi sigmoid or colonoscopy. also, assisting the operator/endoscopist esp in the therapeutic procedure is the nurse's job..but hey, u cant be the jack of all trades, so there should be another nurse or nurse assistant in the room.