Thank you, Dr Gin-Ho Lo, for your comments about our randomized controlled trial (RCT) of Doppler endoscopic probe (DEP) as a guide to improving risk stratification and definitive endoscopic hemostasis of severe nonvariceal upper gastrointestinal hemorrhage (NVUGIH). I offer the following response to help readers put the RCT into perspective. For gastrointestinal clinician-endoscopists, DEP can increase efficacy and reduce workload by improving definitive hemostasis of severe NVUGIH. Our hypothesis, now proven by our prior cohort study and the RCT results, is that arterial blood flow underneath stigmata of recent hemorrhage (SRH) is what determines risks of rebleeding both before and after endoscopic treatment.