RESUMEN
AIM: It is still debated whether clinical flare-ups of chronic inflammatory bowel disease follow a seasonal pattern, and the various reports are based on general practitioners' records or hospital discharge charts. There are, however, no specific figures for treatment in hospital gastroenterology units, which serve as a reference point for these disorders. This study was therefore designed to investigate whether there is a seasonal pattern in admissions for inflammatory intestinal disease in Italy, differing from what is generally known about gastrointestinal pathologies, since there are no nation-wide figures on the subject. METHODS: The RING (Ricerca Informatizzata in Gastroenterologia) project is an observational study collecting hospital discharge forms from 22 centers in Italy. RESULTS: From winter 2000 to autumn 2003, the 22 gastroenterology units participating in the RING project discharged 32,357 patients following ordinary hospital admissions. Of these, 2,856 (8.8%) had a main diagnosis of inflammatory bowel disease: 1,541 Crohn's disease, and 1,315 ulcerative colitis. No seasonal patterns were detected for either category, or when the analysis was done by age, sex and site of disease. CONCLUSIONS: The most serious flare-ups of inflammatory bowel disease, i.e. those requiring routine hospital treatment, do not appear to follow any seasonal pattern, regardless of the site of the disease or the patient's age or sex.