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Intestinal Obstruction

By

Parswa Ansari

, MD, Hofstra Northwell-Lenox Hill Hospital, New York

Last full review/revision Apr 2020| Content last modified Apr 2020
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An obstruction of the intestine is a blockage that completely stops or seriously impairs the passage of food, fluid, digestive secretions, and gas through the intestines.

  • The most common causes in adults are scar tissue resulting from previous abdominal surgery, hernias, and tumors.

  • Pain, bloating, and a loss of appetite are common.

  • The diagnosis is based on the results of a physical examination and x-rays.

  • Surgery to remove the obstruction is often needed.

An obstruction may occur anywhere along the small or large intestine and can be partial or complete. The part of the intestine above the obstruction continues to function. This part of the intestine enlarges as it fills with food, fluid, digestive secretions, and gas. The intestinal lining becomes swollen and inflamed. If the condition is not treated, the intestine can rupture, leaking its contents and causing inflammation and infection of the abdominal cavity (peritonitis Peritonitis Abdominal pain is common and often minor. Severe abdominal pain that comes on quickly, however, almost always indicates a significant problem. The pain may be the only sign of the need for surgery... read more ).

Causes of Intestinal Obstruction

Causes of intestinal obstruction differ depending on the person's age and the location of the obstruction.

In adults, the most common causes overall are bands of internal scar tissue resulting from previous abdominal surgery (adhesions), parts of the intestine bulging through an abnormal opening (hernias Abdominal Wall Hernias An abdominal wall hernia is an opening or area of weakness in the abdominal wall through which abdominal contents can protrude. An abdominal wall hernia causes a noticeable bulging but little... read more Abdominal Wall Hernias ), and tumors. The likelihood of a particular cause varies depending on the part of the intestine affected.

An obstruction of the large intestine is commonly caused by cancer, diverticulitis Diverticulitis Diverticulitis is inflammation of one or more balloon-like sacs (diverticula). Infection may or may not develop. Diverticulitis usually affects the large intestine (colon). Left lower abdominal... read more Diverticulitis , or a hard lump of stool (fecal impaction). Adhesions and volvulus are less common causes of obstruction of the large intestine.

Strangulation

If an obstruction cuts off the blood supply to the intestine, the condition is called strangulation. Strangulation occurs in nearly 25% of people with obstruction of the small intestine. Usually, strangulation results when part of the intestine becomes trapped in an abnormal opening (strangulated hernia Incarceration and strangulation An abdominal wall hernia is an opening or area of weakness in the abdominal wall through which abdominal contents can protrude. An abdominal wall hernia causes a noticeable bulging but little... read more Incarceration and strangulation ), volvulus, or intussusception. Gangrene can develop in as few as 6 hours. With gangrene, the intestinal wall dies, usually causing rupture, which leads to peritonitis, shock, and, if untreated, death.

What Causes Intestinal Strangulation?

Intestinal strangulation (cutting off of the blood supply to the intestine) usually results from one of three causes.

What Causes Intestinal Strangulation?

Symptoms of Intestinal Obstruction

Symptoms of intestinal obstruction usually include cramping pain in the abdomen, accompanied by bloating and loss of appetite. Pain tends to come in waves and eventually becomes continuous. Vomiting is common with obstruction of the small intestine but is less common and begins later with obstruction of the large intestine.

Complete obstruction causes severe constipation, whereas partial obstruction may cause diarrhea.

With strangulation, pain may become severe and steady. A fever is common and is particularly likely if the intestinal wall ruptures.

With volvulus, pain often begins abruptly. Pain is continuous and may come in waves.

Diagnosis of Intestinal Obstruction

  • A doctor's examination of the abdomen

  • X-rays

  • Computed tomography (CT)

A doctor examines the abdomen for tenderness, swelling, or masses. When an obstruction occurs, the abdomen is almost always swollen. The sounds normally made by a functioning intestine (bowel sounds), which can be heard through a stethoscope, may be much louder and higher pitched, or they may be absent. The abdomen is usually not very tender when the doctor presses on it unless rupture has caused peritonitis.

Doctors usually also do imaging studies of the abdomen, such as x-rays or a CT scan.

X-rays X-Ray Studies of the Digestive Tract X-rays often are used to evaluate digestive problems. Standard x-rays (plain x-rays) do not require any special preparation (see Plain X-Rays). These x-rays usually can show a blockage or paralysis... read more may show dilated loops of intestine that indicate the location of the obstruction. The x-rays also may show air around the intestine or under the layer of muscle that separates the abdomen and the chest (diaphragm). Air normally is not found in those places and thus is a sign of rupture or dead bowel.

Treatment of Intestinal Obstruction

  • Suction via nasogastric tube

  • Fluids given by vein

  • Surgery for strangulation

  • Sometimes a colostomy

Anyone suspected of having an intestinal obstruction is hospitalized. Usually, a long, thin tube is passed through the nose and placed in the stomach (called a nasogastric tube) or into the intestine. Suction is applied to the tube to remove the material that has accumulated above the blockage. Fluid and electrolytes Overview of Electrolytes Well over half of the body's weight is made up of water. Doctors think about the body's water as being restricted to various spaces, called fluid compartments. The three main compartments are... read more (sodium, chloride, and potassium) are given by vein (intravenously) to replace water and salts lost from vomiting or diarrhea.

Sometimes an obstruction resolves without further treatment, especially if caused by scarring or adhesions. Occasionally, an endoscope Endoscopy Endoscopy is an examination of internal structures using a flexible viewing tube (endoscope). Endoscopy can also be used to treat many disorders because doctors are able to pass instruments... read more (a flexible viewing tube), which is inserted through the anus, or a barium enema, which inflates the large intestine, may be used to treat some disorders, such as a twisted intestinal segment in the lower part of the large intestine. Most often, however, surgery is done as soon as possible if doctors are concerned about strangulation.

The cause of the obstruction and the appearance of the intestine determine whether the surgeon can relieve the blockage without removing a segment of the intestine. Sometimes adhesions can be cut to release the trapped segment of intestine, but they may re-form and obstruction may recur. In some cases, an ileostomy (a procedure where a cut-off end of the small intestine is permanently attached to a surgical opening in the abdominal wall) or colostomy (a surgically created opening between the large intestine and the abdominal wall—see Figure: Understanding Colostomy Understanding Colostomy An obstruction of the intestine is a blockage that completely stops or seriously impairs the passage of food, fluid, digestive secretions, and gas through the intestines. The most common causes... read more ) is required to relieve an obstruction.

Understanding Colostomy

In a colostomy, the large intestine (colon) is cut. The part that remains connected to the colon is brought to the skin surface through an opening that has been formed. The part is then stitched to the skin. Stool passes through the opening and into a disposable bag.

Understanding Colostomy
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