The purpose of the study is to determine if adding Benadryl improves sedation for patients scheduled to undergo ERCP or EUS procedures.

The usual sedatives used for endoscopy are meperidine (Demerol) and midazolam (Versed). Benadryl (Diphenhydramine) is often used in addition to these medications in an effort to improve sedation. There is little published information regarding the use of diphenhydramine in conscious sedation. It is recognized that certain patients have features that predict difficult sedation such as prescription sedative use or heavy alcohol use. In addition, prolonged procedures like ERCP and EUS require higher doses of sedatives. Diphenhydramine may improve the quality of sedation in patients undergoing endoscopic retrograde cholangio-pancreatography (ERCP) or endoscopic ultrasound (EUS) procedures. You are being asked to participate because you are already scheduled to undergo one of these procedures.

Inclusion Criteria:

• Patients between 18 and 65 years of age who present for outpatient ERCP or EUS at Strong Memorial Hospital Endoscopy Center will be included

Exclusion Criteria:

• Allergy to diphenhydramine, narrow angle glaucoma, or inability to consent