Gastrointestinal symptoms are a common feature of Addison's disease, but the diagnosis may be delayed because of the nonspecific nature of the symptoms. This report describes nine patients with Addison's disease who presented to our unit over the past 3 yr. Eight had severe or unusual gastrointestinal symptoms at presentation. One, already known to have Addison's disease, required several admissions to the hospital because of unexplained abdominal pain and vomiting before inadequate glucocorticoid replacement was diagnosed. All but one had previously attended the hospital, but the diagnosis of Addison's disease had been overlooked. Five eventually presented in crisis. It is important to exclude Addison's disease in all patients with unexplained abdominal symptoms.