CLO test™ is simple, rapid and a commonly used rapid urease test for the diagnosis of H. pylori infection. This study was performed to investigate the content of endoscopic diagnosis and positive rate of CLO test for patients in whom CLO test was performed, and to know if there is any hange of number and result of CLO test according to the year when CLO test was done.

From January 1996 to January 1998, 1,370 cases of CLO test were performed. A gastric biopsy specimen from the greater curvature of antrum within 2cm from pylorus was used for CLO test.

The proportion of performed CLO tests among total endoscopic examinations was 14.1%(1,370/9,709). The most common indication of CLO test was duodenal ulcer, followed by chronic gastritis and gastric ulcer in order. In male, duodenal ulcer was the most common indication of CLO test, while in female, chronic gastritis was the most common. The positive rate of CLO test of total 1,370 cases was 62.0%. The positive rate of CLO test in male was significantly higher than that in female and the 4th decade of age showed the highest prevalence. According to the endoscopic diagnosis, the positive rate of CLO test was the highest in active stage of duodenal ulcer(84.3%), 56.5% in gastric ulcer, 54.6% in chronic gastritis, and 52.8% in gastric cancer. Comparing between 1996 and 1997, the number of CLO test increased, but its positive rate decreased significantly.

Although the most common indication of CLO test was duodenal ulcer in this study, the result that CLO test was also commonly used in chronic gastiritis implies an increasing interest about the role of H. pylori in various gastroduodenal diseases.