http://www.intelihealth.com/IH/ihtIH
Intestinal blockage may occur from a wide variety of clinical conditions, and the evaluation and management of patients with intestinal obstruction can be complex. Intestinal blockage can be defined as the inability to pass intestinal contents through the bowel. A partial blockage suggests that some things can pass through the intestine but that there are still symptoms of blockage. Complete blockages are true medical emergencies that often require urgent surgery, whereas partial blockages may be managed without surgery. Intestinal blockages can be located in either the small intestine or large intestine. It is important to distinguish the site of obstruction, because the causes, symptoms and management of blockages differ depending on location. Overall, the most common symptoms are abdominal pain, vomiting and lack of bowel movements. The most prominent feature is typically abdominal pain, which may be episodic and "colicky." In small bowel blockages, the higher up the intestine the level of blockage, the sooner vomiting will usually occur. The location of pain is typically in the epigastric (upper middle) or umbilical (middle) regions. Pain may occur in paroxysms or waves, at 4-5 minutes intervals for high obstructions and at less frequent intervals for lower obstructions.
The development of continuous and severe localized pain may indicate development of a strangulated obstruction with a lack of blood flow to the bowel. In colonic obstructions pain may be located lower in the abdomen and be more associated with abdominal distension. Depending on the degree of colonic obstruction, patients may experience either diarrhea or constipation. Vomiting, when it occurs, is typically a late sign in colonic blockages.
Seen in 50 to 70 percent of cases, the most common cause of a small-bowel blockage is adhesions. Adhesions are scar tissue, usually due to previous operations in the abdomen. About 25 percent of blockages are caused by hernia. Tumors of the small bowel are a relatively infrequent cause of obstruction, accounting for only about 10 percent of cases.
In contrast, large-bowel obstructions are due to cancer in over half of cases. The other common causes are volvulus (twisting of the bowel), which accounts for about 20 percent of cases; and diverticular strictures, which make up 10 percent of cases.
Treatment of most patients with bowel obstruction will take place in the hospital. Fluids are given intravenously, as patients are unable to take anything by mouth. A nasogastric tube (small tube placed via the nose into the stomach) is frequently used to decompress the stomach and decrease intestinal distension, improving patient comfort. Most patients with complete bowel blockage will go on to have surgery. However, patients with an incomplete or partial bowel blockage may be treated surgically or nonsurgically. Many patients with partial small-intestine blockages due to adhesions will improve with nonsurgical management, typically with dramatic improvement in the first 24 hours of treatment. Patients who fail to improve or worsen with nonsurgical management will need to have surgery.
June 12, 2001