What Is the Most Common Cause of Gastrointestinal Bleeding in Patients with a History of Peptic Ulcer Disease

Mr. Santos, a 55-year-old Male, Presents to the Emergency Department with Complaints of Dark, Tarry Stools for the Past Two Days. He Reports a History of Peptic Ulcer Disease and Takes Nonsteroidal Anti-inflammatory Drugs (Nsaids) Regularly for His Chronic Arthritis. on Examination, He Appears Pale and Has a Rapid Heart Rate. His Blood Pressure Is 90/60 Mmhg. Laboratory Results Show a Low Hemoglobin Level