AIM: To provide the clinical and epidemiological data of inflammatory bowel disease (IBD) patients of North-Eastern Poland. METHODS: A total of 248 IBD patients diagnosed and hospitalized in the Department of Infectious Diseases in Bialystok between 1990 and 2003 were included in the study. We analyzed age, sex, education, characteristics of job, type of the environment, discontinuation of employment due to IBD, colitis extent, need of surgical treatment, and coexistence of other diseases. RESULTS: Two hundred and thirty-three IBD patients (94%) were diagnosed as ulcerative colitis (DC), and only 15 (6%) were diagnosed as Crohn’s disease (CD). Patients with CD were significantly younger at the time of diagnosis and male predominance was observed. The mean age of the patients at the time UC diagnosis was 44.9±1.1 years. Histogram of the age of patients showed the characteristic biphasic distribution with two peaks between 20 and 40 years and between 60 and 70 years. The predominant form of UC was left sided colitis, which affected almost 80% of the studied population. The most extensive form - pancolitis was present in 34 patients (15%). Only 6% of UC patients required surgery, whereas 36% of CD patients underwent surgery (P<0.005). Among coexisting disorders, cholelithiasis was the most prevalent and demonstrated in 35 patients (14%), pulmonary disorders were diagnosed in 2%, and psoriasis in 1.4%. Since 1998, the number of admitted IBD patients has slightly increased. CONCLUSION: Occurrence of UC in Poland is much higher than that of CD. The majority of UC cases are diagnosed in young people (20-40 years) with the predominance of male patients. The most common clinical form of UC is left sided colitis. METHODS: A total of 248 IBD patients diagnosed and hospitalized in the Department of Infectious Diseases in Bialystok between 1990 and 2003 were included in the study: We analyzed age, sex, education, characteristics of job, type of the environment, discontinuation of employment due to IBD, colitis extent, need of surgical treatment, and coexistence of other diseases. RESULTS: Two hundred and thirty-three IBD patients (94%) were diagnosed as ulcerative colitis (DC), and only 15 (6%) were diagnosed as Crohn’s disease (CD). Patients with CD were significantly younger at the time of diagnosis and male predominance was observed. The mean age of the patients at the time UC diagnosis was 44.9 ± 1.1 years. Histogram of the age of patients showed the characteristic biphasic distribution with two peaks between 20 and 40 years and between 60 and 70 years. The predominant for m of UC was left sided colitis, which affected almost 80% of the studied population. The most extensive form - pancolitis was present in 34 patients (15%). Only 6% of UC patients required surgery, while 36% of CD patients underwent of coexisting disorders, cholelithiasis was the most prevalent and demonstrated in 35 patients (14%), pulmonary disorders were diagnosed in 2%, and psoriasis in 1.4%. Since 1998, the number of admitted IBD patients has slightly increased. CONCLUSION: Occurrence of UC in Poland is much higher than that of CD. The majority of UC cases are diagnosed in young people (20-40 years) with the predominance of male patients. The most common clinical form of UC is left sided colitis