Anxiety disorders are serious medical illnesses that affect approximately 20 million adults in the United States. These disorders include generalized anxiety disorder, social anxiety disorder, post traumatic stress disorder, panic disorder and obsessive-compulsive disorder (OCD). Obsessive-compulsive disorder affects approximately 3.3 million adults in the United States, causing patients to experience obsessive thoughts and perform repetitive rituals (e.g. checking, hoarding, hand washing) that interfere with normal life. The obsessive thoughts and compulsions are often irrational and cause significant stress and anxiety, leading to isolation of the individual from work or society, or impaired productivity. Individuals with OCD often recognize their behaviors as excessive or unreasonable. OCD is a chronic condition that usually begins in adolescence or early adulthood. Although patients can be treated with cognitive behavioral therapy and conventional antidepressant or antianxiety drugs, approximately 20% of patients achieve full remission. Secretin may provide an alternative for patients who are refractory to other drug therapies.