In those who acute high gastrointestinal hemorrhage appears, the early ondoscopia (in the course of 24 hours) allows to accurately identify the source of hemorrágica herosiva gastritis, ulceraciones by drugs, etc. The preendoscópico clinical diagnosis of the hemorrhage source is correct in only half of the clients. In clients with corrosive gastritis, the endoscopia allows to determine the extension of the injury. In clients with dispepcia and normal radiological studies that they do not respond to the usual treatment, the buccal endoscopia can show to the presence or absence of upheavals of the motilidad or abnormalitys of the mucosa.