Efficacy and tolerability of micronized purified flavonoid fractions (MPFF) for haemorrhoids: A systematic review and meta-analysis

•Current evidence does not show MPFF has significant effects on haemorrhoid symptoms of pain and itching.•Limited high quality data shows MPFF may improved bleeding associated with haemorrhoid.•No study fulfilled the criteria for high quality evidence to recommend use of MPFF for symptoms of haemorrhoid. To present a systematic review of randomised controlled trials (RCTs) examining the effects of MPFF in the management of haemorrhoid symptoms. Electronic databases including CENTRAL, CINAHL, EMBASE, MEDLINE were searched up to April 2018 for relevant RCTs. Journal and conference proceedings were also searched. Two review authors independently selected trials, extracted data, assessed the risks of bias in included trials and graded the quality of evidence. Meta-analyses were conducted for studies presenting similar outcomes. Ten RCTs involving 1164 participants were included. These RCTs varied in terms of patients’ grade of haemorrhoids, length of trials, and outcome assessed. Most of the studies did not describe adequately the process of randomisation and allocation concealment. The pooled analysis of data from three studies indicated that there was significant difference between groups for the bleeding outcome, favoring the MPFF group (RR 1.46; 95% CI 1.10–1.93; p = 0.008). Except for bleeding, the current evidence did not show MPFF has significant effects on all the other outcomes examined when compared with placebo. Even then, the quality of evidence for bleeding was judged as low due to the small number and inconsistent results among the included studies. This review highlights the need for further rigorous research if MPFF was to be routinely used for the treatment of haemorrhoid symptoms.