This study amis to investigate upper endoscopic findings of typical acid reflux patients with and without alarm symptoms in Taiwan During the period from May 2008 to December 2009, consecutive adult outpatients, who receive upper endoscopy for characteristic reflux symptoms of heartburn or acid regurgitation, are invited to participate. All study participants are evaluated for presence of pre-defined alarm symptoms including odynophagia or dysphagia, gastrointestinal bleeding, involuntary body weight loss and anemia.