A mechanical bowel obstruction is a partial or complete blockage in the intestine. It can happen at any point along the intestine tract but it is more common in the small bowel. The small bowel is the upper part of the intestines and the large bowel is the lower part.
When the bowel is blocked, food and liquid cannot pass through. Over time, food, liquid, and gas build up and cause pressure and pain. Some obstructions, when left untreated, can cut off the flow of blood to the intestine. This can lead to death of the intestine tissue and serious illness.
The bowel is a muscular tube that is constantly moving to push food through. Blockage may be caused by something blocking the inside of the tube or something that stops the intestine from working well.
Most small bowel blockages are due to scar tissue. This tissue connects the bowel to the abdominal wall or other organs. This makes it hard for the bowel to work as needed. Most large bowel obstructions are caused by tumors.
Other causes of bowel obstructions include:
—part of intestine pokes through abdominal wall and squeezes intestine shut
Bowel inflammation or swelling
Foreign matter in the intestines
Impacted feces—bulk of feces becomes trapped in the rectum
Volvulus—twisting of the intestine
—when the intestine pulls inward into itself
, most common cause in children
Factors that may increase your chances o a bowel obstruction:
Previous gastrointestinal or gynecologic surgery—can lead to scarring
You will be asked about your symptoms and medical history. A physical exam will be done. A stethoscope will be placed on your abdomen to listen for bowel sounds. Absent, or abnormal signs may suggest a bowel obstruction.
Images will be needed to confirm the obstruction. This can be done with one or more of the following:
Bowel obstruction. UCSF Department of Surgery website. Available at: https://surgery.ucsf.edu/conditions--procedures/bowel-obstruction.aspx. Updated June 6, 2016. Accessed January 9, 2018.
Jackson P, Raiji M. Evaluation and management of intestinal obstruction. Am Fam Physician. 2011;83(2):159-165.
Last reviewed November 2018 by
EBSCO Medical Review Board
Daus Mahnke, MD
Last Updated: 3/20/2017
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