| Number | Age (years) | Gender (M:F) | |
| Control | 22 | 64 (55–75) | 7:15 |
| IBS | 23 | 53 (30–65) | 3:20 |
| IBS-D | 8 | 34 (26–57) | 1:7 |
| IBS-C | 8 | 59 (49–69) | 2:6 |
| IBS-A | 7 | 65 (24–70) | 0:7 |
Values are the median and interquartile range.
F, female; IBS, irritable bowel syndrome; IBS-A, IBS with an alternating stool pattern; IBS-C constipation-predominant IBS; IBS-D diarrhoea-predominant IBS; M, male.