Intestinal obstruction may be mechanical or non-mechanical (adynamic ileus). Adhesions and external hernias are the most common causes of obstruction in small intestine, whereas carcinoma, sigmoid diverticulitis, and volvulus are the most common causes in large intestine obstruction. Distension of the intestine caused by gas and fluid accumulation in the obstructed segment is the key pathophysiological mechanism initiating ileus with subsequent multiorgan failure and death. Surgery should always be undertaken if complete obstruction or strangulation is suggested and ileus is established. Before operation, the fluid and electrolyte balance should be restored and decompression instituted by means of a nasogastric tube. Delaying the operation because of improvement in patient well-being during resuscitation is only justified in those suffering from large intestine obstruction due to colorectal carcinoma. Purely nonoperative treatment is safe only in the presence of incomplete obstruction and best utilized in patients with postoperative adynamic ileus or repeated episodes of partial obstruction.