A bowel obstruction is a partial or complete blockage of the intestines that prevents the normal passage of substances, including gas, fluids and solids, through the intestines.

A bowel obstruction is characterized by an inability to defecate properly. The urge to defecate is typically present, but something is blocking the stool from exiting the anus. Other symptoms of a bowel obstruction include bloating, abdominal pain, nausea, vomiting and constipation.

A bowel obstruction may result from a mechanical (physical) blockage. A similar condition is an ileus, which is the loss of intestinal peristalsis (movement). Both of these are serious conditions. that requires immediate medical attention. If left untreated, the intestine may rupture and leak its contents, causing inflammation and infection of the abdominal cavity and its lining (peritoneum), a condition called peritonitis.

Common causes of mechanical intestinal obstruction include adhesions, hernias, foreign bodies and fecal impaction, among others. Factors that can increase a patient’s risk of mechanical bowel obstruction include laparotomy (abdominal surgery), inflammatory bowel disease (especially Crohn's disease), diverticular disease, cancer and radiation therapy.

The diagnosis of a bowel obstruction typically involves an evaluation of the patient’s medical history, a physical examination and a series of diagnostic imaging tests (e.g., x-ray, CAT scan). Hospitalization of the patient is always required for the treatment of bowel obstruction.

Treatment will depend on the underlying cause and type of obstruction. In the case of partial obstructions, nonsurgical treatments (e.g., nasogastric aspiration) are usually the first line of treatment. These measures allow the bowel to decompress. Other types of treatment for a partial obstruction include the use of liquids (enemas), small mesh tubes (stents for malignancy) or medications to open up the blockage. 

Abdominal surgery, called laparotomy, is generally necessary for a complete or strangulating obstruction (when blood flow is cut off to the intestine). Procedures to prevent recurrence of a bowel obstruction are also performed during laparotomy. These include the repair of hernias and removal of foreign bodies and adhesions if present.