Donor Versus Autologous Fecal Microbiota Transplantation for Irritable Bowel Syndrome

Inclusion

• Diagnosed with IBS in the primary or secondary health care service

• Aged 18-65 years with IBS defined by the Rome IV criteria:

• Moderate to severe IBS symptoms, as defined by a score of ≥175 on the IBS-SSS

• All participants >50 years: Colonoscopy within the last 5 years prior to study entry including negative mucosal biopsy for microscopic colitis in participants subtyped as IBS-D

Exclusion

• Planned evaluations or examinations for bowel related complaints

• Known presence of:

• Endometriosis or polycystic ovarian syndrome

• Diabetes type 1 and 2

• Systemic disease including

• Morbidly obesity (BMI ≥35)

• Severe autoimmune disease

• Severe immune deficiency (acquired, congenital or due to medication)

• Previous treatment with FMT

• History of:

• Severe psychiatric disorder, alcohol or drug abuse. Mood disorders are allowed as long as there is no reason to believe that it will interfere with the ability to participate in the study.

• Inflammatory bowel disease, microscopic colitis, diverticulitis or ileus

• Abdominal surgery, with the exception of appendectomy, cholecystectomy, caesarean section and hysterectomy

• Malignant disease (excluding basalioma)

• "Red flags'' indicating severe undiagnosed disease including:

• Night sweats (Repeated episodes of extreme perspiration that may soak nightclothes or bedding)

• Unintentional weight loss (≥ 4.5 kilograms, or 5% of normal body weight) over less than 12 months without knowing the reason

• Family history of GI cancer defined as two or more first- or second-degree relatives, with:

• ≥ 1 diagnosed by age 50, OR

• ≥ 3 first- or second-degree relatives with GI cancer diagnosis, independent of age

• Use of the following the previous 4 weeks:

• Drugs with effects on bowel function..Rescue medication, such as Polyethylene glycol (Laxabon, Movieprep, Movicol) or Loperamide is allowed

• Drugs with analgesic action. Use of paracetamol, Non.Steroid Anti-Inflammatory Drugs ≤3 days week is allowed.

• Use of proton pump inhibitors or other antacids ≥3 days week

• Introduction of antidepressants or anxiolytics the last 12 weeks. Patients on a stable dose >12 weeks are eligible.

• Treatment with antibiotics 12 weeks prior to study entry.

• Use of kolestyramin for bile acid malabsorption

• Pregnant, lactating or planning pregnancy.

• Physical exam indicating undiagnosed malignant, autoimmune, or infectious disease

• Laboratory work up indicating undiagnosed digestive, malignant, autoimmune, infectious disease or alternative diagnosis to the IBS related signs and symptoms. The work up includes:

• Full blood count

• Erythrocyte sedimentation rate (ESR)

• C-reactive protein

• Anti-tissue transglutaminase IgA, total IgA

• Lactase genotype

• Stool tests for:

• Occult blood (Hemofec©).

• Fecal calprotectin indicating inflammatory bowel disease. The detection limit that excludes participants will depend on which assays is used for analysis at the different study centers.

• Only if indicated by the patient history (i.e. travelers diarrhea): Stool test for fecal ova and parasite, Clostridoides difficile toxin and pathogenic bacteria (Shigella spp, Salmonella spp. Campylobacter spp, Yersinia spp, and toxin-producing Clostridoides difficile.) All test results must be negative.