Prevalence and severity of abdominal complaints during and or up to 3 hours after running
| Total (n=1993)* | Men (n=891) | Women (n=1095) | P value men versus women† | |
| Prevalence | ||||
| Any abdominal complaints | 1139 (57) | 398 (45) | 738 (67) | <0.001 |
| Any upper abdominal complaints | 302 (15) | 107 (12) | 194 (18) | <0.001 |
| Nausea/vomiting | 149 (8) | 31 (4) | 118 (11) | <0.001 |
| Reflux | 209 (11) | 87 (10) | 121 (11) | <0.001 |
| Any lower abdominal complaints | 1115 (56) | 383 (43) | 729 (67) | <0.001 |
| Side stitch | 466 (23) | 116 (13) | 348 (32) | <0.001 |
| Bloating | 497 (25) | 141 (16) | 354 (32) | <0.001 |
| Flatulence | 726 (36) | 272 (31) | 453 (41) | <0.001 |
| Urge to defecate | 649 (33) | 222 (25) | 426 (39) | <0.001 |
| Faecal incontinence | 141 (7) | 30 (3) | 111 (10) | <0.001 |
| Diarrhoea | 368 (19) | 114 (13) | 254 (23) | <0.001 |
| Constipation | 157 (8) | 22 (3) | 135 (12) | <0.001 |
| Severity score | ||||
| Nausea/vomiting | 19 (3 – 42) | 17 (2 – 48) | 20 (4–42) | 0.742 |
| Reflux | 18 (0 – 37) | 15 (0–34) | 20 (1 – 40) | 0.419 |
| Side stitch | 29 (10–48) | 20 (0 – 40) | 30 (10 – 50) | <0.001 |
| Bloating | 13 (0 – 34) | 15 (0–31) | 11 (0–35) | 0.923 |
| Flatulence | 25 (7–41) | 25 (6–48) | 25 (8–40) | 0.774 |
| Urge to defecate | 40 (19–66) | 30 (10–59) | 45 (21–70) | <0.001 |
| Faecal incontinence | 28 (10–51) | 15 (4–43) | 30 (12–52) | 0.017 |
| Diarrhoea | 21 (3–51) | 12 (0–40) | 30 (7–57) | <0.001 |
| Constipation | 3 (0–21) | 0 (0–10) | 5 (0–23) | 0.041 |
| Total score | 75 (30–145) | 58 (20–110) | 90 (39–164) | <0.001 |
Data are presented as n (%) or median (25th–75th percentile).
*The total population includes five gender-neutral runners and two runners who did not fill in their gender.
†P values for differences in prevalence were obtained with a Pearson χ2 test, and p values for differences in scores with a Mann-Whitney U test; statistical significance (p<0.05) is indicated in bold.