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Intestinal Obstruction

By

Parswa Ansari

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

Reviewed/Revised Apr 2023
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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 bulge but little... read more Abdominal Wall Hernias ), and tumors. The likelihood of a particular cause varies depending on the part of the intestine affected.

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 bulge 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.

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.

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) can show some blockages or paralysis of the digestive tract, or abnormal air patterns in the abdominal cavity... 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 ruptured 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. Fluids and electrolytes Overview of Electrolytes More than half of a person's body weight is water. Doctors think about water in the body as being restricted to various spaces, called fluid compartments. The three main compartments are Fluid... 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 it is caused by scarring or adhesions. Occasionally, an endoscope Endoscopy Endoscopy is an examination of internal structures using a flexible viewing tube (endoscope). In addition to examinations, doctors can use endoscopy to do biopsies and give treatment. Endoscopes... read more (a flexible viewing tube), which is inserted through the anus, or a barium enema Barium enema X-rays often are used to evaluate digestive problems. Standard x-rays ( plain x-rays) can show some blockages or paralysis of the digestive tract, or abnormal air patterns in the abdominal cavity... read more , 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 Understanding Colostomy ) is required to relieve an obstruction.

Understanding Colostomy

In a colostomy, the large intestine (colon) is cut. The healthy end of the large intestine, which is before the blockage, is brought to the skin surface through a surgically created opening in the abdominal wall. It is then stitched to the skin of the opening. Stool passes through the opening and into a disposable bag. The colostomy allows the remaining part of the large intestine to rest while the person recovers. After the person recovers from the surgery and the colon heals, the two ends can be reattached so that stool can pass normally.

Understanding Colostomy
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