This article examines use of the Doppler endoscopic probe (DEP) for risk stratification and as a guide to definitive hemostasis of nonvariceal upper gastrointestinal (NVUGI) bleeding and colonic diverticular hemorrhage. Studies report that lesions with high-risk stigmata of recent hemorrhage (SRH) have a higher rate of a positive DEP signal compared with those without such SRH. Lesions with a persistently positive DEP signal after endoscopic hemostasis have a higher 30-day rebleeding rate. Studies document arterial blood flow underneath stigmata of recent hemorrhage as a risk factor for rebleeding of focal nonvariceal gastrointestinal lesions. With DEP probe as a guide, rates of definitive endoscopic hemostasis and clinical outcomes are improved compared with standard visually guided treatment.