Gastro-Esophageal Reflux Disease was defined as a condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications. Many drugs used for the treatment of GERD such as omeprazole (a proton pump inhibitor) which is widely used anti-ulcer drug and has been demonstrated to protect against esophageal mucosal injury. Melatonin has been found to protect the gastrointestinal mucosa from oxidative damage caused by reactive oxygen species in different experimental ulcer models. The aim of this study is to evaluate the role of exogenous melatonin in the treatment of reflux disease in human either alone and in combination with omeprazole therapy.

Inclusion Criteria:

• patient with GERD ranged from 42 to 56 years

Exclusion Criteria:

• patients with cardiac disease
• patients with renal affection
• patients with liver diseases (due to drug induced, autoimmune disease and viral hepatitis)
• patients on the drugs known to affect the GIT motility (phenothiazines, anticholinergics, nitrates or calcium channel blockers) were excluded during the time of conduction of the study or the preceding two weeks