Symbioflor 2 bacteria for irritable bowel syndrome with diarrhoea compared with placebo

Who can take part

• Male or female outpatients aged ≥18 years • Diagnosis of irritable bowel syndrome according to Rome IV: 1. Recurrent abdominal pain, on average, at least 1 day per week in the last 3 months associated with two or more of the following criteria: - Related to defecation - Associated with a change in frequency of stool - Associated with a change in form (appearance) of stool 2. Criteria fulfilled for the last 3 months and 3. IBS symptom onset ≥6 months 4. IBS-D subtype with abnormal stools being usually diarrhoea • Colonoscopy with no clinically relevant findings (performed for all patients younger than 50 years and for patients ≥50 years of age within the last 5 years) • Female patients of childbearing potential must be either surgically sterilized or use a highly effective method of contraception with a negative pregnancy test at screening and baseline/day 0 • Willingness to refrain from significant changes in diet, fibre intake, fluid intake, or physical activity during the study • Willingness to refrain from the use of other medications for IBS treatment, including probiotic medication • Ability to comply with treatment • Sufficient knowledge of German language to understand trial instructions and rating scales • Written informed consent prior to enrolment • Email account and internet access available

Who cannot take part

• History of abdominal surgery within the 6 months prior to screening • Presence or suspected presence of unstable coronary artery disease, untreated organic gastrointestinal disease and uncontrolled metabolic diseases causing IBS-related symptoms, or collagen vascular disease within the 6 months prior to screening • Lactose or fructose intolerance explaining the symptoms (in doubtful cases, a diagnostic test has to be performed) • Coeliac disease (in doubtful cases, a diagnostic test has to be performed) • Confirmed bile acid malabsorption by SeHCAT-Test or successful treatment by bile acid sequestrant • Change of diet e.g. FODMAP, gluten-free within last 3 months • Abnormal endoscopy/ abdominal ultrasound requiring further investigation • Any alarm symptoms including uninvestigated anaemia, rectal bleeding, weight loss, or unresolved fever within the 6 months prior to screening • Participation in another clinical trial or use of any investigational drug within 30 days or 5 half-lives (whichever is longer) before dosing • Evidence of current or recent alcohol or drug abuse within 6 months prior to screening • History or evidence of current laxative abuse • Pregnancy or breast feeding • Any illness or condition that might impact the safety of study drug administration or evaluability of drug effect based on Investigator’s discretion • No consent to recording and processing of pseudonymised data according to legal requirements • Patients who are committed to a clinic or similar institution by official or judicial order • Hypersensitivity to active ingredient or any excipients of the medicinal product Patients will be excluded from randomization to a treatment group if they have/are: • Current intake of prohibited medications except for rescue purposes (refer to 9.3) • Serum potassium, magnesium, or calcium values outside the normal range at screening and clinically significant • Serum aspartate transaminase (AST), alanine transaminase (ALT), or gamma glutamyl-transferase (GGT) ≥3 times the upper limit of the normal range at screening or baseline, or a bilirubin value ≥2 times the upper limit of the normal range at screening • Abnormal thyroid stimulating hormone (TSH) value at screening, unless the free T4 value is normal; (Note: Levothyroxine will be allowed, if on stable dose for at least 30 days prior to screening and no changes expected during study) • Any further laboratory value(s) outside the laboratory reference range at screening considered clinically significant by the Investigator