Intestinal obstructions are a potentially serious condition where the intestines are blocked. If blockage occurs, food and drink cannot pass through the body. Both the small intestine and large intestine (colon) can be affected. Obstructions are considered an emergency and may require surgery.
Intestinal obstruction is the partial or complete blockage of the intestines at one or more locations. Obstructions prevent liquids and solids from passing through the digestive tract. There are a variety of causes. These can include mechanical blockages, swallowed objects, infections, and nervous system disorders.
This can be an emergency. If the intestines are blocked, that part of the intestine can die. Dehydration can also be a dangerous complication.
Obstruction can be partial, which may resolve without surgery. A complete blockage will likely need intestinal surgery.
Mechanical obstructions physically block 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 in newborns
- Tumors within the small intestine
- Gallstone (rare)
- 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 (large intestine). This can occur due to:
- Impacted stool
- Colon cancer
- Meconium plug in newborns
- Volvulus and intussusception
- Diverticulitis: inflammation or infection of bulging pouches of intestine
- Stricture: narrowing caused by scarring or inflammation
Non-mechanical obstruction can occur when the muscles or nerves within the small or large intestine no longer function. This is called paralytic ileus. The intestines 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 like gastroenteritis or appendicitis
- some opioid pain medications, antidepressants, and antimuscarinic medications
- decreased potassium levels, other mineral/electrolyte imbalances
- Parkinson’s disease and other nerve and muscle disorders
- Hirschsprung disease (lack of nerves in a section of intestine in newborns)
Unfortunately, the symptoms of intestinal obstruction are common to a variety of problems. It takes time and testing to determine whether or not an intestinal obstruction exists.
Symptoms can include:
- severe abdominal pain
- cramps that come in waves
- nausea and vomiting
- 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 the 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:
- Computed tomography (CT scan)
- CT Scan with contrast (CT enterography)
- Barium enema
Treatment must be rapid to prevent complications like:
- electrolyte imbalances
- hole forming in the intestines (perforation)
If the obstruction is preventing blood from getting to a segment of intestine, this can lead to infection, tissue death, or gangrene. In newborns or premature infants, there is a worry that paralytic ileus can become necrotizing entercolitis, a potentially fatal die-off of the intestinal walls.
Treatment depends on the location and severity of the obstruction. For partial obstructions, it may be possible to give a low-fiber diet and wait for the obstruction to pass.
Treating dehydration is important. IV fluids may be started to correct electrolyte imbalance. A catheter may be inserted into the bladder to remove fluid.
In some cases, a tube can be passed through the nose and down into the throat, stomach, and intestines to relieve pressure, swelling, and vomiting. Surgery may still be required after this procedure.
For some patients, 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.
Paralytic ileus may get better without surgery. A patient may be monitored for a few days in the hospital before any surgery is attempted. Medications to improve muscle contractions may be administered.
If the obstruction is mechanical and no other options are available, the abdomen may be cut into. The affected section of intestine is then repaired or removed, and the surrounding intestine reattached.