Demographics and baseline characteristics
| Overall N (%) (n=1123) | WAS N (%) (n=561) | CO2 N (%) (n=562) | |
| Participant age* | 55 (0.41) | 55 (0.36) | 55 (0.45) |
| Gender | |||
| Men | 562 (50) | 279 (50) | 283 (50) |
| Women | 561 (50) | 282 (50) | 279 (50) |
| Hysterectomy | |||
| Women with hysterectomy | 81 (7) | 43 (8) | 38 (7) |
| Women without hysterectomy | 480 (43) | 239 (43) | 241 (43) |
| History of IBS | |||
| No | 1006 (90) | 502 (90) | 504 (90) |
| Yes | 117 (10) | 59 (10) | 58 (10) |
| Diverticulosis | |||
| No | 888 (79) | 458 (82) | 430 (77) |
| Grade 1 (<15, no rigidity or no stenosis) | 194 (17) | 89 (16) | 105 (19) |
| Grade 2 (>15 or rigidity or stenosis) | 38 (3) | 13 (2) | 25 (4) |
| Missing | 3 (<1) | 1 (<1) | 2 (<1) |
| Scope diameter | |||
| Adult | 986 (88) | 492 (88) | 494 (88) |
| Paediatric | 137 (12) | 69 (12) | 68 (12) |
| Trust | |||
| North Tees and Hartlepool Hospitals NHS Trust | 673 (60) | 336 (60) | 337 (60) |
| Northumbria Healthcare NHS Foundation Trust | 177 (16) | 88 (16) | 89 (16) |
| County Durham and Darlington Foundation Trust | 132 (12) | 68 (12) | 64 (11) |
| London North West Healthcare NHS Trust | 80 (7) | 39 (7) | 41 (7) |
| South Tyneside Foundation Trust | 61 (5) | 30 (5) | 31 (6) |
*Mean (SD) reported.
NHS, National Health Service; WAS, water assisted sigmoidoscopy.