RESUMO
BACKGROUND@#Syndrome is one of the most important concepts in Chinese medicine (CM) theory. However, it was not well accounted in most of randomized controlled trials (RCTs).@*OBJECTIVES@#To determine whether CM syndrome differentiation affects the treatment results, functional constipation (FC) was selected as a target disease, and MaZiRenWan (, MZRW), a classic CM formula commonly used for constipation with excessive heat syndrome, was selected for study.@*METHODS@#It is an 18-week prospective double-blinded, doubledummy RCT, including 2-week run-in, 8-week treatment and 8-week post treatment follow-up. A total of 120 FC patients diagnosed as excessive heat syndrome will be recruited from the First Teaching Hospital of Tianjin University of Traditional Chinese Medicine and the Baokang Affiliated Hospital of Tianjin University of Traditional Chinese Medicine. Patients will be randomly allocated into fixed MZRW (f_MZRW) granule group, modified MZRW (m_MZRW) granule group or bisacodyl group. For m_MZRW group, no more than two herbal granules can be added according to the syndrome differentiation for individual participants. The primary end point is the mean of complete spontaneous bowel movements (CSBMs) per week during the treatment period. Secondary end points include mean of CSBMs per week during follow-up, stool form, global symptom improvement, constipation and constipation-related symptoms assessment, CM syndrome change, and reported adverse events.@*DISCUSSION@#This trial is designed to evaluate the effectiveness of these three interventions for FC patients with the CM syndrome of excessive heat, and to determine the change of CM syndrome and the progress of disease during the treatment course. The results are important to explore whether syndrome differentiation is important for the therapeutic effect of a formula on a disease. [Trial registration: Chinese Clinical Trial Registry (Reg No. ChiCTR-TRC-13003742); protocol version: MZRW/NSFC-81173363 (2015.05.04)].