Anti-reflux surgery is indicated when drug treatment fails and when complications of the disease appear. Endoscopy is very important for this evaluation as it allows the doctor to look inside the esophagus and stomach and take biopsies. Drug-refractory gastroesophageal reflux disease tends to progress to esophagitis, which can cause changes in the inner lining of the esophagus, such as ulcerations, metaplasia and dysplasia (Barrett's Disease), which in some cases can progress to cancer. The surgery aims to control the symptoms, stop the aggression to the esophagus and stop the progression of the disease.