Inclusion Criteria:  Healthy individuals ages 18 - 65 inclusive who are indicated for a polysomnography study.  Exclusion Criteria:  Patients with a history of abdominal surgery and/or any condition that may impact the GI tract, including but not limited to:  Constipation Esophageal stricture Esophagitis Gastritis Gastric ulcers Peptic ulcer Gallstones Celiac Disease Crohn's Disease Ulcerative Colitis Irritable Bowel Syndrome Hemorrhoids Anal fissures Diverticulitis Colon polyps Colorectal cancer