Darwin's illness: a final diagnosis.

We have re-examined many of the abundant publications on the illness that afflicted Charles Darwin during most of his life, including some of the 416 health-related letters in his correspondence, as well as his autobiographical writings. We have concluded that he suffered from Crohn's disease, located mainly in his upper small intestine. This explains his upper abdominal pain, his flatulence and vomiting, as well as his articular and neurological symptoms, his 'extreme fatigue', low fever and especially the chronic, relapsing course of his illness that evolved in bouts, did not affect his life expectancy and decreased with old age, and also the time of life at which it started. It apparently does not explain, however, many of his cutaneous symptoms. We do not support other diagnoses such as Chagas' disease, lactose intolerance or the many psychiatric conditions that have been postulated.