Bowel Obstruction

In the large intestine, the most common causes of bowel obstruction are:

• Colorectal cancer - About half of all large-bowel obstructions are caused by colorectal cancer. Undiagnosed colon or rectal cancer may cause a gradual narrowing of the large intestine's inner passageway. Usually patients experience intermittent constipation for a while before the bowel finally becomes obstructed.

• Volvulus - Volvulus is an abnormal twisting of a segment of bowel around itself. This twisting motion typically produces a closed loop of bowel with a pinched base, leading to intestinal obstruction. In Western countries, volvulus is most common among people over age 65, and these patients often have a history of chronic (long-lasting) constipation.

• Diverticular disease - In the large bowel, diverticula are small, balloon-shaped pouches that protrude from the wall of the intestine. If diverticula become infected, a condition called diverticulitis, scars may form in the wall of the colon as it heals. A scar that encircles the colon is called a colon stricture. As a stricture ages and tightens, it can narrow the intestine gradually, eventually causing a blocked colon.

Symptoms

Symptoms of small-bowel obstruction can include:

• Cramping abdominal pain, generally coming in intense waves that strike at intervals of five to 15 minutes and sometimes center either on the navel or between the navel and rib cage (Pain that becomes constant may be a symptom of bowel strangulation)

• Nausea and vomiting

• No gas passing through the rectum

• A bloated abdomen, sometimes with abdominal tenderness

• Rapid pulse and rapid breathing during episodes of cramps

Symptoms of large-bowel obstruction can include:

• A bloated abdomen

• Abdominal pain, which can be either vague and mild, or sharp and severe, depending on the cause of the obstruction

• Constipation at the time of obstruction, and possibly intermittent bouts of constipation for several months beforehand

• If a colon tumor is the cause of the problem, a history of rectal bleeding (such as streaks of blood on the stool)

• Diarrhea resulting from liquid stool leaking around a partial obstruction