A bowel obstruction prevents the contents of the intestines from moving normally. Symptoms of bowel obstruction can be severe, requiring urgent treatment.
A bowel obstruction can originate inside or outside of the small bowel (small intestine) or the large bowel (colon or large intestine). However, the condition is most likely to affect the small intestine.
There are several causes of bowel obstruction — some resulting in a partial blockage and others causing total obstruction. However, all bowel obstructions prevent food, liquid, gas, and stool from moving through the intestines normally.
That explains why symptoms of bowel obstruction primarily center on the gastrointestinal tract. Depending on the cause and size of the blockage, symptoms of a bowel obstruction can indicate a medical emergency.
Bowel obstruction causes
The two most common causes of bowel obstruction in adults are adhesions (fibrous bands of tissue that form after abdominal surgery) and cancer, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
While your internal organs and tissues normally shift easily when you move because they have slippery surfaces, scar-like adhesions can cause tissues inside the abdominal cavity to stick together. This can result in a blockage when loops in the intestines stick to each other, to the abdominal wall, or nearby organs.
Some adhesions cause no problems, but others cause symptoms of bowel obstruction, ranging from constipation to severe abdominal pain and a total blockage of the intestines.
Tumors growing inside or outside of the intestine can result in partial or complete obstructions, too. Malignancies of the colon, stomach, and ovary all can cause intestinal blockages, the National Cancer Institute points out. In fact, obstructions in the large bowel are caused by undiagnosed colon or rectal cancer about half of the time.
In addition, cancer patients who have had surgery on their abdomen or radiation therapy to the abdomen have an increased risk of a bowel obstruction.
Other causes of bowel obstruction:
- A hernia can form when part of the small intestine protrudes through an area in the abdomen with weak muscles and tissues, causing a blockage. Although it’s not common, the hernia may cut blood supply off to the intestine — a condition, known as strangulation, which constitutes a medical emergency.
- Volvulus, an abnormal twisting of a segment of the bowel, can cause a closed loop of the intestines, leading to obstruction. It’s most common in people over the age of 65 who have a long history of constipation.
- Diverticulitis, infection and inflammation of small, balloon-like pouches inside the large bowel (diverticula), can cause strictures — bands of scars that encircle part of the colon. Over time, a stricture can tighten and narrow, resulting in a blockage.
Seek treatment for bowel obstruction symptoms
While adhesions may cause no symptoms and a partial obstruction may only cause some constipation, a complete bowel obstruction is a potentially dangerous situation.
The NDDK advises seeking emergency care if you have these symptoms of bowel obstruction:
- Severe abdominal pain or cramping
- Abdominal bloating
- Nausea and vomiting
- Loud bowel sounds
- The inability to have a bowel movement or pass gas
- Chronic, severe constipation (bowel movements, if they occur, may be painful)
Abdominal x-rays, a lower gastrointestinal series of x-rays (which use a barium enema to make an underlying obstruction show up more clearly in images), and CT scans are used to diagnose intestinal blockages.
Remember: Symptoms of bowel obstruction must be taken seriously. A complete intestinal obstruction is life-threatening and requires immediate medical attention and often surgery.
May 31, 2019
Janet O’Dell, RN