Irritable bowel syndrome (IBS) is a common chronic gastrointestinal disorder which can significantly affect patients’ quality of life. Various factors seem to be involved in the development of IBS, of which an imbalanced gut flora appears to be one. Faecal microbiota transplantation (FMT, the implantation of gut bacteria from a healthy donor to a person whose gut bacterial balance is disrupted) has been used successfully in IBS patients in some but not other clinical trials. The aim of this open-label study was to establish whether IBS patients who were non-responders to a 30g dose of FMT from a “superdonor” (a healthy person with a favourable bacterial composition) would respond to a 60g transplant from the same donor. The ten patients provided a stool sample before and 1 month after FMT to evaluate their bacterial composition. Questionnaires on symptoms, fatigue and quality of life were completed before and at 2 weeks, 1 and 3 months after FMT. Seven of the ten patients who had not responded to the 30g dose of FMT, responded to a 60g dose, with improvements in IBS symptom, fatigue and quality of life scores, as well as dysbiosis index determined with the stool samples. The authors conclude that FMT is an effective treatment for IBS. They point out that success is dependent on the availability of a “superdonor” and that high-dose and/or repeating FMT are required.