What is an intestinal obstruction?

An intestinal obstruction is a potentially serious condition in which the intestines are blocked. The blockage may be either partial or complete, occurring at one or more locations. Both the small intestine and large intestine, called the colon, can be affected. When a blockage occurs, food and drink cannot pass through the body. Obstructions are serious and need to be treated immediately. They may even require surgery.

There are a variety of causes for intestinal obstructions. These can include:

  • scar tissue in the abdomen
  • twisting of the intestines
  • swallowed objects

Sometimes there may be no actual obstruction, but the bowels behave as if they are obstructed. This is called pseudo-obstruction. Among its potential causes are:

  • infections
  • nervous system disorders

An intestinal blockage can be an emergency, especially if the intestine is twisted, because it can cut off the blood supply and cause part of the intestine to die. Dehydration can also be a dangerous complication and can lead to organ failure, shock, and death.

Obstruction can be partial, which may resolve without surgery. A complete blockage is more likely to need intestinal surgery.

Mechanical obstructions

Mechanical obstructions are when something physically blocks the small intestine. This can be due to:

  • adhesions: fibrous tissue that develops after abdominal surgery
  • volvulus: twisting of the intestines
  • intussusception: “telescoping,” or pushing of one segment of intestine into the next section
  • malformations of the intestine occurring in newborns
  • tumors within the small intestine
  • gallstones, which can — but rarely do — cause obstructions
  • swallowed objects, especially in children
  • hernias: a portion of the intestine that protrudes outside of the body or into another part of the body
  • inflammatory bowel disease, such as Crohn’s disease

Though rare, mechanical obstructions can also block the colon, or large intestine. This can be due to:

  • impacted stool
  • colon cancer
  • meconium plug in newborns
  • volvulus and intussusception
  • diverticulitis: the inflammation or infection of bulging pouches of intestine
  • stricture: a narrowing in the colon caused by scarring or inflammation

Nonmechanical obstruction

Nonmechanical delays in transit or obstructions can occur when the muscles or nerves within either the small or large intestine function poorly. This is process is called paralytic ileus if it’s an acute or self-limiting condition. It’s known as intestinal pseudo-obstruction if it becomes chronic. The intestines normally work in a coordinated system of movement. If something interrupts these coordinated contractions, it can cause a functional intestinal obstruction.

Causes for paralytic ileus include:

  • abdominal or pelvic surgery
  • infections, such as gastroenteritis or appendicitis
  • some medications, including opioid pain medications, antidepressants, and antimuscarinics
  • decreased potassium levels
  • mineral and electrolyte imbalances

Intestinal pseudo-obstruction can be caused by:

Unfortunately, the symptoms of intestinal obstruction are common to a variety of problems. It takes time and testing to determine whether an intestinal obstruction exists.

Symptoms can include:

  • severe abdominal pain
  • cramps that come in waves
  • bloating
  • nausea and vomiting
  • diarrhea
  • constipation, or inability to have a bowel movement
  • inability to pass gas
  • distention or swelling of the abdomen
  • loud noises from the abdomen
  • foul breath

First, a doctor may push on your abdomen. They will then listen with a stethoscope to any sounds being made. The presence of a hard lump or the particular kinds of sound produced, especially in a child, may help determine whether or not an obstruction exists. Other tests include:

  • X-ray
  • computed tomography, called a CT scan
  • CT scan with contrast, called CT enterography
  • barium enema

Treatment depends on the location and severity of the obstruction.

For partial obstructions or an ileus, it may be possible to treat by simply resting the bowels and giving intravenous (IV) fluids. Bowel rest means you’ll be given nothing to eat, or clear liquids only, during that time.

Treating dehydration is important. IV fluids may be started to correct electrolyte imbalance. A catheter may be inserted into the bladder to remove fluid.

A tube may need to be passed through the nose and down into the throat, stomach, and intestines to relieve:

  • pressure
  • swelling
  • vomiting

If your problem is due to the use of narcotic pain medications, your doctor can prescribe medication that reduces the effect of the narcotics on the bowels.

Surgery will be required if these measures fail.

Treatment is essential to reduce complications such as:

  • dehydration
  • electrolyte imbalances
  • perforation: a hole that forms in the intestines, which leads to infections
  • kidney failure

If the obstruction is preventing blood from getting to a segment of intestine, this can lead to:

  • infection
  • tissue death
  • intestinal perforation
  • sepsis
  • multisystem organ failure
  • death

For some patients with a chronic obstruction due to a stricture or narrowing of the intestine, a metal stent that expands inside the intestine may be placed using a long tube called an endoscope. This wire mesh holds open the intestine. The procedure may not require cutting into the abdomen, and it’s usually only used if the patient is not a candidate for traditional surgery.

An intestinal blockage is a potentially serious medical condition. The blockage may be either partial or complete, and it may occur in either the small or large intestine. Depending on its severity, it may prevent food and drink from passing through your body. A complete intestinal blockage is a medical emergency and often requires surgery. Sometimes, a partial blockage may resolve on its own. Medications and various procedures may help. If you think you have a blockage, immediate medical attention is necessary.