The meaning of ileus. Its changing definition over three millennia.

Ileus comes from the Greek word for twisted. The early classical literature suggests that this term was used for what we now call sigmoid volvulus. The Romans translated this word as volvulus. During later classical times, investigators used ileus and volvulus in describing conditions other than sigmoid volvulus. Roman investigators used ileus to describe midgut volvulus, intussusception, and incarcerated hernias because the symptoms of these conditions were similar. During the Renaissance, ileus, volvulus, and intussusception were synonymous and were closely linked to the volgar terms iliac passion and Miserere Mei. The sine qua non of ileus was the clinical triad of abdominal pain, obstipation, and fecal vomiting. Autopsies in the 16th, 17th, and 18th centuries exposed the various causes of these symptoms. Ileus became the clinical diagnosis whereas such terms as intussusception were used to describe autopsy findings. Physicians classified diseases by symptoms not by cause. During the 19th century, emphasis switched to the pathologic basis of disease. The classification of intestinal obstruction became one of cause. Ileus was abandoned because its classical definition did not encompass all forms of intestinal obstruction. In the last 50 years, ileus has been relegated to mean nonmechanical obstruction that does not initially require operative treatment. Thus, ileus which was the twisted intestine of Ascelpiades, the Miserere Mei of Paré and the iliac passion of Barrough, has come in the 20th century to mean nonmechanical intestinal obstruction.