&NA;Sigmoid volvulus usually affects the elderly, but it is being increasingly described in a younger age group. In these patients the diagnosis is often delayed, due to a prolonged and intermittent history. Three patients, of 31, 36, and 67 years, are described here, and they demonstrate an increased incidence within families, which has not been previously recognized. A wareness of this possibility may allow earlier diagnosis when investigating young patients with intermittent abdominal symptoms, whose relatives are known to be affected.