A syndrome consisting of a flulike illness with fever, chills, malaise, and inflammatory papules and pustules of 2 to 4 mm in diameter occurs in up to 20% of patients who have had a jejunoileal bypass operation. During most of these episodes, myalgias and polyarthralgias occur. An identical clinicopathologic syndrome may occur in association with other gastrointestinal diseases. In the patient described in this report, this syndrome developed after a gastrointestinal surgical procedure that resulted in a small stomach (70% removed) and a Roux-en-Y jejunostomy.