Intestinal Obstruction: Causes, Risk Factors, and Why It Is Dangerous

When people speak of intestinal obstruction, they usually mean a situation in which the intestine stops passing its contents — acute intestinal obstruction. In this state, food or stool cannot move through the intestine. Below are the causes, the risk group, and the signs that make the situation an emergency.

What intestinal obstruction is

Intestinal obstruction occurs when food or stool does not pass through the intestine. The blockage may be complete or partial. There are many causes. One form of obstruction is intussusception (a separate condition, not obstruction): one part of the intestine invaginates into the lumen of another. At first this is a blockage from within, and after 6–12 hours impaired blood supply to the intestine may develop due to compression of the mesentery.

Main causes of intestinal obstruction

The most common causes of obstruction:

• adhesions — bands of scar tissue that bind loops of intestine to each other, to neighboring organs, or to the abdominal wall;
• hernias;
• tumors;
• certain medications.

Adhesions appear after abdominal surgery — in almost everyone who has undergone such an operation. They can displace loops of intestine and block the passage of contents. In intussusception, the trigger is a disturbance of peristalsis: it is caused by age-related features of connective tissue in infants or by an obstacle in the intestinal wall — inflammation, a pedunculated polyp, a foreign body.

Risk factors and who is affected more often

The risk is higher in those who have undergone surgery on abdominal organs. Intussusception is more common in infants: 85–90% of cases occur before the age of one year, especially at 4–9 months. In children older than one year it is rare and more often associated with an organic cause — a diverticulum, lymphoid hyperplasia, a polyp, a malignant neoplasm. The risk is increased by the intestinal form of allergy, cystic fibrosis, disorders of nervous and humoral regulation, enteroptosis, tuberculosis of the peritoneum and intestine, viral intestinal infections, and complications after surgery on the organs of the gastrointestinal tract.

Signs that should raise concern

Common symptoms of obstruction: severe abdominal pain or cramps, vomiting, bloating, loud bowel sounds, abdominal distension, inability to pass gas, constipation.

In a child with intussusception, everything begins suddenly. The child is restless, cries, and pulls the legs up. The attack ends as abruptly as it began: the child calms down and may play. After a while the attack repeats. Such attacks of pain occur in 90% of cases. Soon vomiting appears once or twice. The temperature usually remains normal. At first the stool is normal, but after 6–10 hours blood appears in it, and it takes on the appearance of "redcurrant jelly." Later, gas and stool stop passing. Between attacks the abdomen is soft, not distended, and sometimes a formation of soft-elastic consistency resembling a sausage can be palpated.

Call 103 or 112 if, against a background of abdominal pain and vomiting, the abdomen is distended and tense, gas and stool are not passing, a child has repeated attacks of restlessness with legs pulled up, or blood has appeared in the stool. Complete intestinal obstruction is life-threatening.

How obstruction is diagnosed

The doctor examines the abdomen, clarifies whether gas and stool are passing, and asks about past operations. Among the examinations used are X-ray tests of the gastrointestinal tract and computed tomography — CT enterography. In a child, the examination is completed with a rectal examination: after the finger is withdrawn, mucus with blood but without admixture of stool may be released. Adhesions themselves cannot be detected by tests — doctors usually find them during surgery or laparoscopy.

Why this is an emergency

Complete blockage blocks the passage of contents entirely. In intussusception, compression of the mesentery impairs blood circulation in the segment of intestine: edema develops, then necrosis. Inflammation glues the cylinders together, and the intussusception can no longer be reduced. With late diagnosis, a picture of peritonitis develops: the abdomen is distended, tense, and sharply painful in all regions. With complete obstruction, the person needs immediate medical help, often surgery. With partial blockage, the doctor determines the approach.

This is reference material: it helps to recognize the signs but does not replace consultation with a doctor.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer