Small bowel obstruction is a leading cause of admission in surgical and emergency units. During the last two decades, the classical philosophy of "never let the sun set or rise on small-bowel obstruction" has been succeeded by a new management based especially on the cause and the severity of the obstruction. It most often allows a correct choice between medical therapy and surgery using laparotomy or laparoscopy. This changing attitude is still in progress and is mainly related to the high accuracy of computed tomography. This review will discuss the semiology and value of computed tomography compared with clinical examination and other imaging modalities.