| Participating hospitals | |
| Gia-Dinh People’s hospital, n (%) | 226 (27.9) |
| Cho-Ray hospital, n (%) | 356 (43.9) |
| Dong-Nai General hospital, n (%) | 43 (5.3) |
| Can-Tho Central hospital, n (%) | 55 (6.8) |
| Bach-Mai hospital, n (%) | 51 (6.3) |
| Hue Central hospital, n (%) | 40 (4.9) |
| Da-Nang General hospital, n (%) | 40 (4.9) |
| Age (mean, SD) | 61 (18.4) |
| Sex | |
| Male, n (%) | 420 (51.8) |
| Previous admission with ALGIB, n (%) | 196 (24.2) |
| Comorbidities | |
| Congestive heart failure, n (%) | 26 (3.2) |
| Ischemic heart disease, n (%) | 109 (13.4) |
| Chronic obstructive pulmonary disease, n (%) | 11 (1.4) |
| Chronic liver disease, n (%) | 86 (10.6) |
| Chronic kidney disease, n (%) | 56 (6.9) |
| Stroke or transient ischemic attack, n (%) | 44 (5.4) |
| Cancer, n (%) | 69 (8.5) |
| Hypertension, n (%) | 309 (38.1) |
| Diabetes, n (%) | 113 (13.9) |
| Pre-admission medications | 163 (20.1) |
| Aspirin, n (%) | 25 (3.1) |
| Clopidogrel, n (%) | 40 (4.9) |
| Dual antiplatelet, n (%) | 25 (3.1) |
| Warfarin, n (%) | 10 (1.2) |
| NOAC, n (%) | 12 (1.5) |
| Corticosteroid, n (%) | 16 (2) |
| NSAIDs, n (%) | 42 (5.2) |
| Vital signs at admission | |
| Heart rate (beat per minute), median (range) | 86 (50 - 140) |
| Heart rate ≥ 100/min, n (%) | 157 (19.4) |
| Systolic blood pressure (mmHg), median (range) | 120 (50 - 190) |
| Systolic blood pressure < 100 mmHg, n (%) | 92 (11.3) |
| Presenting symptoms | |
| Melena, n (%) | 124 (15.3) |
| Bright blood per rectum, n (%) | 498 (61.4) |
| Maroon colored stool, n (%) | 187 (23.1) |
| Stool with clots, n (%) | 9 (1.1) |
| Abdominal pain, n (%) | 224 (27.6) |
| Syncope, n (%) | 4 (0.5) |
| Diarrhea, n (%) | 119 (14.7) |
| Fever, n (%) | 36 (4.4) |
| Blood on digital rectal examination, n (%) | 332 (40.9) |
| Laboratory data at admission | |
| Hematocrit (%), median (range) | 30.4 (5.0 - 62.9) |
| Hematocrit < 35%, n (%) | 537 (66.2) |
| Haemoglobin (g/L), median (range) | 98 (4 - 173) |
| Haemoglobin ≤ 100 g/L, n (%) | 350 (51.54) |
| Platelet (x103/μL), median (range) | 242 (10 - 948) |
| Platelet ≤ 150 × 103/μL, n (%) | 131 (16.2) |
| INR, median (range) | 1.07 (0.8 - 12.4) |
| INR ≥ 1.5, n (%) | 53 (6.5) |
| Blood urea nitrogen (mg/dl), median (range) | 14 (3 - 129) |
| Creatinine (mg/dl), median (range) | 0.98 (0.2 - 13) |
| Creatinine ≥ 1.5 mg/dl, n (%) | 73 (9) |
| BUN/creatinine, median (range) | 14.8 (1.2 - 72) |