Number (%) of subjects rating itemised adverse effects during or after flexible sigmoidoscopy as moderate or severe as recorded on the morning after the test
| Adverse effect | Welwyn Garden City (n=335) | Leicester (n=734) | p(trend)9-150 |
| Abdominal pain | 63 (19) | 87 (12) | <0.001 |
| Nausea/vomiting | 3 (1) | 7 (1) | 0.7 |
| Faint/dizzy | 9 (3) | 15 (2) | 0.6 |
| Wind | 166 (50) | 181 (24) | <0.001 |
| Anal irritation | 22 (7) | 75 (10) | 0.003 |
| Incontinence | 14 (4) | 37 (5) | 0.9 |
| Sleep disturbance | 7 (2) | 55 (7) | 0.0002 |
↵9-150 For differences between centres in rating of adverse effects from none, mild, moderate to severe.