Efficacy of Rifaximin-α vs Dietary Fiber on the evolution of uncomplicated colonic diverticular disease

Abstract

Background: Life expectancy is increasing, technology progress and technique improvements allow performing more colonoscopies in more patients, and these circumstances determine an increasing rate of diagnosing diverticular disease (DD). The more is diagnosed, the better the respective patients will be followed in order to prevent the severe complications of this anatomical disease: Diverticulitis, recurrences, bleeding, perforation, septic peritonitis, even death. Present statistics reveal that the number of patients who suffer a recurrence of diverticulitis is higher than in the past (around 20 % at 5 years) which increases the risk of more severe complications within the respective patients. Treatment of DD of the colon is still, not completely standardized because of a lack of both solid and recent evidences and on the other hand due to the present guidelines which give indications not always unique. The best studied treatment solutions in symptomatic uncomplicated diverticular disease (SUDD) are dietary fibers and Rifaximin-α, but most of the studies are supporting the combination of the two. Recently, more and more controversies emerged regarding the usage of fibers in DD and these new circumstances motivated the initiation of the present study. Objective: Head-to-head comparison between Rifaximin-α and dietary fibers in order to evaluate their efficacy and safety in patients with SUDD. Material and methods: The patients diagnosed with SUDD who fulfilled the inclusion criteria were randomized into two groups: Group 1 received Rifaximin-α 800 mg/day, group 2 received a fiber food supplement (20 gr/day). For both groups the treatment approach was a cyclic one: 10 days each month over a period of 9 months. Clinical evaluation was performed using interviews and questionnaires at inclusion and then every 3 months throughout the study. The biologic systemic inflammatory profile of each patient was also evaluated at inclusion and at the end of study period. Results: For the final analysis, 165 patients were included in Rifaximin-α group and 100 patients in dietary fiber group. Both therapies proved clinical benefit in reducing symptoms (lower abdominal pain, tenesmus, bloating, diarrhea), with a higher efficacy for Rifaximin-α. The global symptomatic score at the end of 9 month treatment period showed a highly significant reduction in favor of Rifaximin-α in comparison with dietary fibers, both in intention to treat (group 1: 3.31±2.68 vs 9.57±5.05, p<0.0001; group 2: 5.36±4.45 vs 10.14±4.48, p<0.0001) and per-protocol analysis (group 1: 3.50±2.56 vs 9.72±4.10, p<0.0001; group 2: 6.32±4.21 vs 10.45±4.63, p<0.01). Moreover, the comparison of the biochemical parameters at the beginning and at the end of the study shows a highly significant reduction of the inflammatory systemic profile only within the group treated with Rifaximin-α. Regarding the complications, there were 5 cases registered in group 1 (rectal bleeding in 3 cases, diverticulitis in 2 cases) and 9 cases in group 2 (rectal bleeding in 2 cases, diverticulitis in 4 cases, intestinal infections in 3 cases). Regarding the secondary effects, we registered a single case within group 1 (headache and nausea, symptoms which remitted after interrupting the medication). Conclusion: Rifaximin-α alone (800 mg/day, 10 days/month, each month) proves a better efficacy than dietary fibers in improving the clinical evolution of uncomplicated colonic diverticular disease, in improving the quality of life of respective patients and in reducing disease complications. If it is well chosen and managed, soluble fiber diet regimen plays also a beneficial role in SUDD.