Heritability of irritable bowel syndrome based on estimated population prevalence and tetrachoric correlation in case-control study according to Frisell et al 37
| Exposed cases | Unexposed cases | OR | Prevalence | Tetrachoric correlation | Heritability (%) |
| 26 | 543 | 1.67 | 0.5 | 0.08 | 16 |
| 26 | 543 | 1.67 | 1.0 | 0.09 | 17 |
| 26 | 543 | 1.67 | 3.0 | 0.10 | 20 |
| 26 | 543 | 1.67 | 5.0 | 0.11 | 22 |
| 26 | 543 | 1.67 | 10.0 | 0.12 | 24 |
| 26 | 543 | 1.67 | 15.0 | 0.125 | 25 |
| 26 | 543 | 1.67 | 20.0 | 0.133 | 27 |