Scientists probe gut bugs and sugar link in IBS pain

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: For all groups: * Patients with IBS defined by current Rome criteria (currently IV) * Adult, aged 18 to 75 * Regulatory criteria : * Membership of a social security scheme * Adult having read and understood the information letter and signed the consent form * Woman of childbearing age with effective contraception for the duration of the study such as oestroprogestins, intrauterine device, tubal ligation, vasectomised partner or sexual abstinence (no heterosexual intercourse for 1 month and a negative urine pregnancy test at inclusion). * Postmenopausal women: confirmatory diagnosis (non-medically induced amenorrhoea for at least 12 months prior to the inclusion visit or biologically documented) * Women of childbearing age who have been rendered surgically infertile (e.g. hysterectomy, bilateral salpingectomy, bilateral oophorectomy). For the IBS group with fructose malabsorption and visceral hypersensitivity (named group of interest, MalF-HyperSens) (1): * 25g fructose breath test in favour of fructose malabsorption * Rectal barostat finding visceral hypersensitivity For the IBS group with fructose malabsorption and without visceral hypersensitivity (known as the MalF-NormoSens group) (2): * Fructose breath test at 25g dose in favour of fructose malabsorption * Rectal barostat finding no visceral hypersensitivity For the IBS group without fructose malabsorption and visceral hypersensitivity (named NormoF-HyperSens group) (3): * Fructose breath test at 25g dose in favour of no fructose malabsorption * Rectal barostat finding visceral hypersensitivity For the IBS group without fructose malabsorption or visceral hypersensitivity (called the NormoF-NormoSens group) (4): * Fructose breath test at a dose of 25g in favour of the absence of fructose malabsorption * Rectal barostat finding no visceral hypersensitivity Exclusion Criteria: * Patient who has not undergone a fructose breath test or a barostat in our department in the last 10 years. * Patient with organic digestive pathology (chronic inflammatory bowel disease, microscopic colitis, digestive cancer, celiac disease) * Systemic antibiotic use (oral, IV or IM) in the month prior to inclusion * Regulatory criteria : * Pregnant or parturient or breast-feeding woman or proven absence of contraception, * Person deprived of liberty by an administrative or judicial decision or person placed under court protection / sub- guardianship or curatorship, * Person undergoing research participating in another trial / having participated in another trial within a period of 2 weeks, * History of illness or psychological or sensory abnormality likely to prevent the subject from fully understanding the conditions required for participation in the protocol or preventing him/her from giving informed consent.