Objectives: The specific aims (SA) of this research are: #1) In a randomized, blinded prospective controlled (RCT) study of patients with severe UGI hemorrhage (from varices/portal hypertensive lesions as one separate group vs. ulcers, & other benign non-variceal sources as another group) to compare 30 day outcomes of patients in these 2 major disease groups, managed by current standards (according to endoscopic visualization & stigmata of hemorrhage) with similar patients assessed, risk stratified, & treated with DEP monitoring. #2). For patients randomized to the DEP group, to determine the initial prevalence, type (arterial or venous), & location & course of blood flow underlying stigmata for the different lesion groups. #3). For DEP patients with different lesion types, to determine the rates of persistent blood flow after endoscopic hemostasis treatments & whether blood flow after under stigmata can be eliminated by further endoscopic hemostasis with different techniques. #4). To determine the proportion of patients whose risk stratification (for rebleeding) &/or endoscopic treatment are changed by utilizing DEP for detection of blood flow under stigmata of hemorrhage or lesions before as a guide for endoscopic treatment & absence of flow after treatment as a treatment endpoint rather than visual guidelines (stigmata) alone for endoscopic treatment. #5). To compare the outcomes for a large cohort of historical controls previously treated for hemostasis of the two lesion types in the UGI tract by the CURE/VA Hemostasis Research Group according to visual guidelines & stigmata alone with patients in the RCT managed with DEP findings & stigmata, contrasting demographics, hemostasis rates, rebleeding rates & other outcomes up to 30 days for major diagnoses (ulcers and other non-variceal lesions vs varices & other lesions related to portal hypertension). #6). For patients who are treated with surgery or angiography for continued bleeding or rebleeding of UGI lesions, to correlate & compare their vessel depth & location (relative to stigmata), type of vessel, & lumen patency at surgery or angiography vs. Doppler endoscopic probe findings recorded previously. Research Plan and Methods: All studies will be performed over 5 years. The investigators will utilize a large RCT (blinded), a very large cohort study, & prospective observational studies to complete the specific aims of the study. Statistical Analysis System (SAS) will be utilized for data management. For SA #1, about 240 new patients (150 with non-variceal lesions and 90 with variceal-portal hypertensive lesions) admitted to West Los Angeles (WLA) VA or UCLA Hospitals with severe UGI hemorrhage will be randomized in RCT of Doppler assisted management versus standard endoscopic/medical diagnosis, risk stratification, & treatment. During urgent endoscopy, patients with clean varices (as the source of bleeding) or other UGI lesions with stigmata of recent hemorrhage (from the ulcers, Mallory Weiss tears, esophageal or gastric varices, and Dieulafoy's lesions) will be randomized. Routine clinical outcomes will be assessed prospectively & compared by major diagnostic groups (ulcers-non-variceal lesions or varices-portal hypertensive lesions). For SA #5 (UGI cohort study), demographics, outcomes, & risk factors will be compared for about 150 patients with non-variceal lesions & about 90 other variceal-portal hypertensive lesion matched historical control patients (from CURE Hemostasis Research Databases) treated previously only based upon stigmata vs. 75 new patients with non-variceal UGI lesions or 50 variceal-portal hypertension lesions in this study treated according to stigmata of hemorrhage & DEP as a guide to risk stratification & endoscopic hemostasis. SA #2-4 & 6 will be prospectively performed according to the methods in the proposal & all analysis will be performed with the collaboration of an experienced biostatistician.