Subjects: The sample was obtained from subjects who were referred for diagnostic upper endoscopy after showing symptoms suggestive of acid peptic disease. All procedures were performed by an endoscopist.
Sujetos: La muestra se obtuvo de los sujetos que fueron remitidos para practicar una endoscopia digestiva alta para diagnóstico, por presentar síntomas sugestivos de enfermedad ácido péptica y se realizaron todas por un solo endoscopista.