Table 2. Etiology of LGIB.
| Late colonoscopy | Early colonoscopy | Total | |
| Primary diagnosis | |||
| Diverticular bleeding | 193,938 (43.3) | 204,549 (55.8) | 398,487 (48.9) |
| Anorectal hemorrhage | 119,761 (26.8) | 97,685 (26.5) | 217,446 (26.7) |
| Intestinal arteriovenous malformations | 42,448 (9.5) | 22,791 (6.2) | 65,240 (8.0) |
| Dieulafoy lesion | 1,808 (0.4) | 1,842 (0.5) | 3,650 (0.4) |
| Unspecified LGIB with secondary etiologies | 89,850 (20.1) | 39,974 (10.9) | 129,824 (15.9) |
| Polyps | 63,039 (14.1) | 24,153 (6.6) | 87,192 (10.7) |
| Non-infectious colitis | 8,747 (1.9) | 4,244 (1.2) | 12,991 (1.6) |
| Colonic ulcer | 5,683 (1.3) | 3,946 (1.1) | 9,629 (1.2) |
| Ischemic colitis | 4,387 (0.9) | 2,713 (0.7) | 7,100 (0.8) |
| Inflammatory bowel disease | 3,233 (0.7) | 2,288 (0.6) | 5,521 (0.7) |
| Solitary rectal ulcer | 2,851 (0.6) | 1,649 (0.4) | 4,500 (0.5) |
| Colorectal cancer | 2,148 (0.5) | 1,296 (0.4) | 3,443 (0.4) |
| Gastrointestinal vessel anomaly | 1,227 (0.3) | 567 (0.2) | 1,795 (0.2) |
| Anal fissure | 636 (0.1) | 408 (0.1) | 1,043 (0.1) |
| Infectious colitis | 495 (0.1) | 365 (0.1) | 860 (0.1) |
LGIB, lower gastrointestinal bleeding.