The evolution of knowledge regarding the anatomy of the intestine throughout Greece-Arabic period and the Modern period is described. The common opinions of this organ at various points throughout this timeline are shown. The original words of great physicians from the period of time stretching from Ancient Egypt to the Avicenna era and hakim Kābbiruddin are quoted and discussed to demonstrate how knowledge of the intestine has evolved. Unani Medicine is a medical system that treats with the management of health and disease. Jalinus (Galen, 200 AD) observed that Small intestine heal more quickly and with lesser complications than wounds of the large intestine because of good blood supply. Avicenna stated that duodenal mucosa lacked the circular folds of mucosa (plicae circulares) found in the jejunum and ileum. According to Avicenna, the jejunum has a abundant blood vessels. It consisting of large, tall and closely packed circular folds of mucosa than the ileum.