HKBU and CUHK expand joint clinical study of Chinese herbal medicine for functional constipation

6 May 2013


The research team led by Professor Bian Zhaoxiang of the School of Chinese Medicine, together with Professor Justin Wu’s team at the Institute of Digestive Disease, The Chinese University of Hong Kong (CUHK), completed a 4.5-year joint research project in 2010. A total of 120 functional constipation patients took part in the clinical study and used the classic Chinese medicine formula of MaZiRenWan (MZRW or Hemp Seed Pill) to treat functional constipation. The results of the study point to the efficacy of MZRW in treating constipation without causing apparent side effects. Professor Bian and Professor Wu shared the results of the study with the media today (6 May). The results have been previously published in the renowned American Journal of Gastroenterology in 2011. Please click here for details.


Constipation is a common gastrointestinal complaint in clinical practice, affecting a number of people in busy cities with a fast pace of life. A survey conducted by The University of Hong Kong in 2005 revealed that about 14 per cent of Hong Kong people suffer from constipation, and 27 per cent of the global population is estimated to be affected. With the current mainstream medical treatment which is symptomatic in nature yielding unsatisfactory results, many patients have been turning to Chinese medicine in recent years. 


Based on this collaborative study, the research teams at HKBU and CUHK have recently received further funding from the Food and Health Bureau to jointly launch an ongoing project to compare the efficacy and safety of MZRW with traditional Western medicine and placebo. The formula of MZRW has been commonly used for excessive constipation in China since the Han Dynasty (A.D. 200). It is a mixture of Fructus Cannabis, Radix et Rhizoma Rhei, Semen Armeniacae Amarum, Radix Paeoniae Alba, Cortex Magnoliae Officinalis, and Fructus Aurantll Immaturus.


Professor Bian Zhaoxiang said: “We first conducted a comprehensive evaluation on the efficacy of this classic Chinese medicine formula MZRW on functional constipation, then implemented a dose determination study followed by a placebo-control trial, and finally compared MZRW with an active conventional control trial. We hope the study can be a reference to other evidence-based research on Chinese herbal medicine interventions in the future, helping to promote the standardisation and internationalisation of Chinese medicine.”

The research team is now recruiting 291 qualified functional constipation patients for a 18-week clinical trial. All the treatment and tests are free. Those aged 18-65 years, and free of significant illnesses but who experience difficulty in bowel movements (three defecations per week) are invited to join. For details, please visit website:


Professor Bian Zhaoxiang (left) and Professor Justin Wu jointly announce the clinical study of Chinese herbal medicine for functional constipation

The formula of MaZiRenWan is a mixture of Fructus Cannabis, Radix et Rhizoma Rhei, Semen Armeniacae Amarum, Radix Paeoniae Alba, Cortex Magnoliae Officinalis, and Fructus Aurantll Immaturus