Study design
The present randomized, double-blinded, placebo-controlled clinical trial was executed according to the declaration of Helsinki and good clinical practice guidelines. The ethics committee of Shiraz University of Medical Sciences, Shiraz, Iran permitted the protocol (IR.SUMS.REC.1396.98). This study was also registered in the Iranian Registry of Clinical Trials (IRCT20170916036204N7) and was conducted between October 2017 and September 2018. Patients who were referred to the gastroenterology clinic of Motahari polyclinic, Shiraz University of Medical Sciences, Shiraz, Iran, and met the inclusion criteria were comprised in the present study.