Table 1.

Eligibility criteria

Type	Inclusion criteria	Exclusion criteria
IBD	Patients with documented CD, UC or IBD-U, >4 years old	Patients with subtotal colectomy and/or ileostomy Major comorbid condition where the projected survival is less than 5 years Difficulties with communication, including unable to communicate in English or French Diagnosis of schizophrenia Diagnosis of eating disorder
IBS	Patients with IBS who have met Rome IV criteria, ≥13 years old IBS-D Normal CBC Negative tissue transglutaminase antibody if diarrhoea the main symptom Symptoms onset >45 years old, then negative colonic biopsies for microscopic colitis IBS-C, IBS-M and IBS-U Negative tissue transglutaminase antibody Symptoms onset >50 years age, with new symptoms <1-year duration, then have a negative colonoscopy, CT colonography or Air Contrast Barium Enema Normal CBC	Major GI surgery (Roux en y, bowel resection) Major comorbid condition, where the projected survival is less than 5 years Drug use that is the major cause of GI symptoms and/or undermines longitudinal compliance, including chronic antibiotic use, narcotic analgesics and substance abuse Narcotic analgesic use causing GI symptoms Difficulties with communication, including unable to communicate in English or French Diagnosis of schizophrenia Diagnosis of eating disorder GI cancer within 5 years
Healthy controls	No GI symptoms using the Rome IV Questionnaire	Major GI surgery (Roux en y, bowel resection) Any major comorbid chronic condition Difficulties with communication, including unable to communicate in English or French Diagnosis of schizophrenia Diagnosis of eating disorder

CBC, complete blood count; CD, Crohn’s disease; GI, gastrointestinal; IBD, inflammatory bowel disease; IBD-U, unclassified IBD; IBS, irritable bowel syndrome; IBS-C, constipation-predominant IBS; IBS-D, diarrhoea-predominant IBS; IBS-M, IBS with mixed bowel habits; IBS-U, unclassified IBS; UC, ulcerative colitis.