Efficacy of fecal microbiota transplantation in patients with post-infection irritable bowel syndrome with diarrhea
Authors: Fadieienko G. D. , Gridnyev O. E. , Dubrov K. Y. 
Published: June 2022

Objective — to evaluate efficacy of potentiation of remission and safety of fecal microbiota transplantation (TFM) in patients with post‑infection irritable bowel syndrome with predominance of diarrhea (PI — IBS‑D), in whom standard therapy was ineffective.
Materials and methods. The study involved 16 patients with patients with moderate to severe PI — IBS with diarrhea who did not respond to standard therapy and did not have any significant comorbidities. The diagnosis of IBS was made according to the Rome IV criteria. IBS severity was assessed with the use of Irritable bowel syndrome — Severity Scoring System, and the frequency of defecation and stool consistency according to the Bristol scale. Donor selection, preparation for TFM and the procedure itself were carried out in accordance with the recommendations of the European Consensus on TFM (2017). TFM was performed once with a colonoscope in the right part of the large intestine — 180 ml of a solution prepared from 50 g of donor feces. The total follow‑up period was 6 months after TFM. Efficacy was assessed by the level of score reduction of the IBS‑SSS questionnaire — a decrease of 50 points or more was considered a significant improvement. During the observation period, the patient did not take any additional drugs and procedures.
Results. The obtained results showed a positive TFM effects on the clinical manifestations of post‑infection IBS, resistant to standard therapy. After 1 month post transplantation, the severity of symptoms decreased by more than 75 IBS‑SSS points in 75 % of patients and 3 of them had remission. The TFM procedure resulted in a significant decrease compared to baseline in the severity of abdominal pain (37 points) and its duration (31 points), bloating (41 points), dissatisfaction with defecation (40 points) against the background of almost twofold reduction in the frequency of defecation from 3.68 to 1.81 bowel movements/day) and improved stool consistency according to the Bristol scale (from 6.81 to 5.21 points). These rates remained unchanged until the end of the third month after TFM, they did not differ significantly compared to the end of the first month: 75 % of patients experienced adequate relief of abdominal pain, satisfaction with defecation, reduced bloating and reduced impact on quality of life. However, by the end of 6th month, the symptoms of PI — IBS began to increase: the average score of IBS‑SSS increased to 169 points, including indicators of the intensity of abdominal pain and its duration, severity of bloating, dissatisfaction with defecation and defecation frequency, thus PI — IBS increasingly affected the quality of life of patients. Despite the increased PI — IBS severity by the end of 6th month after TFM, its symptoms remained significantly lower than before treatment and still 62.5 % of patients reported adequate relief of abdominal pain and satisfaction with defecation, reduction of diarrhea and bloating. None of patients reported about serious adverse events. During the first hours after procedure, only 31.25 % trial participants noticed insignificant adverse events (abdominal discomfort, flatulence and stomach growling) that disappeared on their own during the day.
Conclusions. Colonoscopy‑delivered fecal microbiota transplantation proved to be effective and safe procedure in patients with PI — IBS who have not responded to standard therapy.