“…The criteria of the Forrest classification [2,3] and the Rockall score [7] a We modified the diagnostic criteria of comorbidities as follows to make this variable clearer to be scored than it was according to the old criteria b Cardiac failure included congestive heart failure with New York Heart Association Function I to IV c Any major comorbidity included lung disease (chronic obstructive pulmonary disease, pulmonary tuberculosis, pneumonia, or empyema), chronic kidney disease stage III (estimated glomerular filtration rates between 30 and 60 mL/min/1.73 m 2 ), rheumatoid arthritis, sepsis, newonset cerebrovascular accident, intensive care unit stay, mechanical ventilator support for > 24 h, or any major surgery (on the central nervous system, thorax, abdomen, long bones or spinal bones) within 14 days prior to bleeding d Liver failure included liver cirrhosis, Child-Pugh A, B, or C e Renal failure included chronic kidney disease stage IV (estimated glomerular filtration rates between 15 and 30 mL/min/1.73 m 2 ), stage V (estimated glomerular filtration rates < 15 mL/min/1.73 m 2 ) with or without maintenance dialysis, or acute kidney injury with estimated glomerular filtration rates < 30 mL/min/1.73 m 2 Previous studies have shown that comorbid patients have impaired tissue healing on peptic ulcers [8][9][10]. Studies have also shown that patients' Rockall scores are often ≥ 6 in those with comorbidities, who also exhibit an increased risk of recurrent peptic ulcer bleeding [11,12]. Therefore, we propose that patients with Rockall scores ≥ 6 are still at risk of recurrent bleeding after initial treatment partially because of impaired tissue healing, which results in delayed fading out of the Forrest lesions.…”