Ankylosing spondylitis and inflammatory bowel disease. I. Prevalence of inflammatory bowel disease in patients suffering from ankylosing spondylitis.

To establish the prevalence of inflammatory bowel disease in ankylosing spondylitis (AS), 79 AS patients underwent detailed medical screening, including sigmoidoscopic and roentgenological examination, 48 had gastrointestinal symptoms and the others did not. In 3 patients a diagnosis of Crohn's disease was made which was previously established. In all other patients inflammatory bowel disease could be excluded. The prevalence of inflammatory bowel disease in this series of patients with AS therefore was 3.8%.