Intestinal Obstruction: What It Is, Causes, and Types

Intestinal obstruction is a partial or complete blockage of the intestine: the contents of the bowel cannot move onward. Below: what blocks the path, how the types differ, and why urgent medical assessment is needed.

Intestinal Obstruction: What It Is

The intestine is a tube through which food, and then stool, moves. In obstruction, movement stops: partially or completely. Both the small and large intestine can be affected. "Bowel blockage" and "blocked bowel" are everyday names for the same condition.

The obstruction may be real, or there may be no obstruction but the intestine is not working. In the first case, something physically blocks the lumen. In the second, the lumen is open, but the intestinal wall does not contract — motility has shut down.

Causes of Intestinal Obstruction

The most common causes are adhesions, hernias, tumors, and certain medications. Most often the cause is surgery on abdominal organs.

Mechanical causes: adhesions and scar tissue after surgery, hernias, tumors compressing the lumen, foreign bodies, fecal masses, volvulus, intussusception (one segment of intestine telescopes into another), inflammatory diseases such as Crohn's disease. Less commonly — gallstones.

Dynamic causes: abdominal surgery, intestinal infections, electrolyte disturbances (for example, low potassium), reduced blood supply to the intestine, inflammation in the abdominal cavity such as appendicitis, kidney and lung diseases, use of certain medications, especially narcotic painkillers.

Types: Mechanical and Dynamic Obstruction

Mechanical obstruction — there is an obstruction. It accounts for approximately 5–15% of cases of severe abdominal pain that arises suddenly and requires hospitalization.

Dynamic (ileus) — there is no obstruction; motor function is impaired. The paralytic form, or pseudo-obstruction, is one of the main causes of obstruction in infants and children. The spastic form occurs in lesions of the brain or spinal cord and in poisoning with heavy metal salts.

The mechanical form has predisposing anatomical features: congenital dolichosigmoid, mobile colon, additional peritoneal pockets and folds, adhesions, elongation of the sigmoid colon in older age, hernias. An episode can also be triggered by dietary load: a large high-calorie meal, a large volume of food after prolonged fasting.

How Acute Intestinal Obstruction Manifests

The picture consists of several signs. The abdomen is distended, feels bloated, and gas accumulates. Pain is cramping. Loud bowel sounds appear. Nausea occurs, and vomiting is possible. Gas does not pass, and there is no stool. The list of possible manifestations also includes diarrhea and constipation, as well as bad breath.

How a Doctor Confirms the Diagnosis

The doctor examines the abdomen: looking for distension, tenderness, hernia. Next are instrumental examinations: abdominal CT, X-ray, barium enema, fluoroscopy of the upper gastrointestinal tract and small intestine.

Ask the surgeon about four things:

• which examinations are needed specifically in your case and in what order;
• whether X-ray is sufficient or CT is needed;
• what exactly is visible on the images and where the level of obstruction is;
• how the approach will change if the condition does not improve.

Why Obstruction Is Dangerous and When to Call an Ambulance

Obstruction is dangerous not only because of the stasis itself. Fluid and salts are lost through vomiting and move into the intestinal lumen — if the problem is unresolved, losses reach 4 liters per day or more. This leads to dehydration and electrolyte disturbances.

Possible complications: intestinal perforation, infection, jaundice. If the blood supply to a segment of intestine is blocked, gangrene develops. The risk is higher with hernia, volvulus, and intussusception. In newborns, the paralytic form with destruction of the intestinal wall is a life-threatening condition. Complete obstruction is an emergency, and surgery is often required. If the abdomen is distended and this does not resolve, vomiting recurs, or abdominal pain persists without a clear cause — this is a reason to seek medical help urgently.

Complete intestinal obstruction is an emergency. 103/112 — if there is no stool or gas at all and severe abdominal pain and vomiting have appeared.

This is reference material, not a substitute for medical consultation: the decision in your case is made by a surgeon.

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