The study included 52 children aged 8-18, treated with bismuth salts (Ventrisol-tripotassium dicitrato bismuthate) 1 tablet (120 mg Bi23) 4 times a day for 28 days, because of chronic gastritis or duodenal ulcer and Helicobacter pylori infection. Bismuth concentration in blood and urine was determined in all the patients before the treatment, on 6-8th day, 10-12th day, 27-28th day as well as on 1-3rd day, 1 month and 1.5-4 months after the treatment completion. We observed trace amount of bismuth in blood and urine before the therapy, its increase in blood until the 10-12th day of treatment, its similar amounts maintained later on, and a stable rise of bismuth amount excreted with urine. After treatment completion, there was a slow drop of bismuth concentration in blood and urine. 3 children suffered from unfavourable side effects during the treatment.

Keywords: Bismuth, childre, Urine, Blood