Table 1

Demographics and clinical characteristics of study subjects

Case–control cohorts
Sweden Italy US (Mayo) US (UCLA) Total
IBSCTRLIBSCTRLIBSCTRLIBSCTRLIBSCTRL
N3873553192551871141381321031856
Mean age, year4242.539.634.847.946.635.033.541.439.4
% F:M82:1843:5773:2768:3291:967:3375:2558:4280:2056:44
IBS-D1271598942417
IBS-C951285645324
IBS-M162324134269
IBS-U30117321
PopCol Total IBS* CTRL* Microbiota Diary
N25030163136133
Mean age, year53.651.654.754.854.7
% F:M64:3660:4059:4162:3865:35
IBS-D11
IBS-C5
IBS-M9
IBS-U5
  • *IBS cases (IBS) and asymptomatic controls (CTRL) were identified based on questionnaire data according to Rome criteria.

  • Diary, subjects with available daily recordings of defaecation patterns used for correlation analysis with the Val15Phe variant and stool frequency; Microbiota, subjects with available faecal 16S sequencing data; IBS-C, constipation-predominant IBS; IBS-D, diarrhoea-predominant IBS; IBS-M, IBS mixed phenotype; IBS-U, unclassified IBS; PopCol, Population-based Colonoscopy Study; UCLA, University of California, Los Angeles.