Obstruction of the bowel may be due to:

• A mechanical cause, which means something is partially of fully blocking the bowel
• Ileus, a condition in which the bowel does not work correctly, but there is no structural problem causing the obstruction

Paralytic ileus, also called pseudo-obstruction, is one of the major causes of intestinal obstruction in infants and children. Causes of paralytic ileus may include:

• Bacteria or viruses that cause intestinal infections (gastroenteritis)
• Chemical, electrolyte, or mineral imbalances (such as decreased blood potassium level)
• Abdominal surgery
• Decreased blood supply to the intestines
• Infections inside the abdomen, such as appendicitis
• Kidney or lung disease
• Use of certain medicines, especially narcotics

Mechanical causes of intestinal obstruction may include:

• Adhesions or scar tissue that form after surgery
• Foreign bodies (objects that are swallowed and block the intestines)
• Gallstones (rare)
• Hernias
• Impacted stool
• Intussusception (telescoping of one segment of bowel into another)
• Tumors blocking the intestines
• Volvulus (twisted intestine)
• Inflammatory diseases such as Crohn disease
  

Symptoms may include:

• Abdominal swelling (distention)
• Abdominal fullness, gas
• Abdominal pain and cramping
• Breath odor
• Constipation
• Diarrhea
• Inability to pass gas
• Nausea and vomiting

During a physical exam, the health care provider may find bloating, tenderness, or hernias in the abdomen.

Tests that show obstruction include:

• Abdominal CT scan
• Abdominal x-ray
• Barium enema
• Upper GI and small bowel series

Treatment involves placing a tube through the nose into the stomach or intestine. This is to help relieve abdominal swelling (distention) and vomiting. Volvulus of the large bowel may be treated by passing a tube into the rectum.

Surgery may be needed to relieve the obstruction if the tube does not relieve the symptoms. It may also be needed if there are signs of tissue death. If a tumor is causing a mechanical obstruction, surgery may be needed. Obstruction from inflammation such as Crohn disease may be treated with surgery, a procedure to dilate the narrow area, or medicine if inflammation is causing a blockage.

The outcome depends on the cause of the blockage. Most of the time, the cause is successfully treated.

Complications may include or may lead to:

• Electrolyte (blood chemical and mineral) imbalances
• Dehydration
• Hole (perforation) in the intestine
• Infection
• Jaundice (yellowing of the skin and eyes)

If the obstruction blocks the blood supply to the intestine, it may cause infection and tissue death (gangrene). Risks for tissue death are related to the cause of the blockage and how long it has been present. Hernias, volvulus, and intussusception carry a higher gangrene risk.

In a newborn, paralytic ileus that destroys the bowel wall (necrotizing enterocolitis) is a life-threatening condition. It may lead to blood and lung infections.

Contact your provider if you:

• Cannot pass stool or gas
• Have a swollen abdomen (distention) that does not go away
• Keep vomiting
• Have unexplained abdominal pain that does not go away

Prevention depends on the cause. Treating conditions, such as tumors and hernias that can lead to a blockage, may reduce your risk.

Some causes of obstruction cannot be prevented.

Paralytic ileus; Intestinal volvulus; Bowel obstruction; Ileus; Pseudo-obstruction - intestinal; Colonic ileus; Small bowel obstruction

Galandiuk S, Netz U, Morpurgo S, et al. Colon and rectum. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 21st ed. Philadelphia, PA: Elsevier; 2022:chap 52.

Gan T, Evers BM. Small intestine. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 21st ed. Philadelphia, PA: Elsevier; 2022:chap 50.

Mustain WC, Turnage RH. Intestinal obstruction. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 123.

Updated by: Jenifer K. Lehrer, MD, Department of Gastroenterology, Aria - Jefferson Health Torresdale, Jefferson Digestive Diseases Network, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.