A patient has been suffering from buttock and abdominal discomfort every month for years. A specialist discovers the reason: it is often stubbornly hidden. Recorded by Diana Helfrich

A woman was referred to us by a resident vascular doctor. The 40-year-old told her story: She had had pain in her buttocks and abdomen for a long time, especially on the right side, sometimes stronger and sometimes weaker, which came mainly when sitting and at night. It had first happened about ten years earlier, just before she became pregnant. Since then, she has often felt the blood pulsing between her buttocks and labia at night, and she cooled the region.