The main cause of intestinal obstruction due to problems outside the wall of the intestine is, adhesions.
Adhesions are due to healing from previous injury and inflammation. They are
beneficial when it comes to walling off areas of inflammation and infection,
but they can also cause harm by;
There is no doubt that adhesions cause mechanical intestinal obstruction. In fact, they are the commonest cause of small bowel obstruction [MPM+87,TW95]. Adhesions are mainly found following previous surgery. But, they may also be seen following previous inflammation, eg. surrounding a gall bladder that has previously suffered from acute cholecystitis. A congenital variety also exist.