Introduction: Data about clinical trials on digestive diseases are very few. Quality of clinical trials can reflect to some degree the level of clinical care. It is therefore necessary to understand the current status of clinical trials and sort out issues related to these diseases. "Chinese Journal of Digestion " is an exclusive, high-grade professional journal of digestive diseases with authority in China.

Objectives: To find out randomized controlled trials(RCTs) from clinical trials on digestive diseases published in "Chinese Journal of Digestion " for constituting baseline data in this fields.

Methods: Page by page handsearching was used in identifying RCTs amongst clinical trials from Jan, 1981 (start publication) to Dec, 1998 of "Chinese Journal of Digestion ", with 94 issues and 18 volumes. The definition of RCT and controlled clinical trial (CCT) was strictly based on the ones in "The Cochrane Collaboration Handbook

Results: 68 RCTs were identified from 277 clinical, trials, with a percentage of 24.54%. Among 68 RCTs, 16 were double-blinded and 14 multi-center collaboration trials. The average sample sizes of the RCTs was 92.7 +-83.7 cases(21-440). The ratio of RCTs was increased each 5 years, i.e. 10.9%(6/55) in 1981-1985, 21.33%(16/75) in 1986-1990, 32.71%(35/107) in 1991-1995. The numbers of multi-center collaboration trials were gradually increased. The major digestive diseases studied in 68 RCTs included esophageal variceal bleeding, reflux esophagitis, Barrett esophagus, chronic gastritis, peptic ulcer, gastrointestinal hemorrhages, irritable intestinal syndrome, hepatic cirrhosis, hepatic encephalopathy, chronic hepatitis B, acute pancreatitis etc.

Discussion: The quality of clinical trials on digestive diseases in China still has to be improved. More RCT and double-blind method as well as multi-center, large-scale collaborative trials should be used.