What causes obstructed bowel

What is a Bowel Obstruction?

A bowel obstruction is a serious medical condition that prevents food and liquid from passing through your small or large intestine. The intestines are part of your digestive system, responsible for absorbing nutrients from food and eliminating waste. When an obstruction occurs, this process is interrupted, leading to a buildup of pressure and a lack of blood supply to the affected bowel segment. This can cause severe pain, vomiting, and potentially life-threatening complications.

Types of Bowel Obstruction

Bowel obstructions can be classified in several ways:

• By Location: They can occur in the small intestine or the large intestine (colon). Small bowel obstructions are more common than large bowel obstructions.
• By Completeness: An obstruction can be partial, meaning some material can still pass through, or complete, where nothing can get through. Partial obstructions may resolve on their own or with conservative treatment, while complete obstructions usually require surgery.
• By Cause: The underlying reason for the blockage dictates the specific type of obstruction.

Common Causes of Bowel Obstruction

The causes of bowel obstruction are diverse and depend on whether the obstruction is in the small or large intestine.

Causes of Small Bowel Obstruction:

• Adhesions: These are the most frequent cause of small bowel obstruction, particularly in adults. Adhesions are bands of scar tissue that can form after abdominal surgery. They can cause the bowel to kink or become trapped. It's estimated that up to 70% of small bowel obstructions are due to adhesions.
• Hernias: A hernia occurs when an organ or tissue pushes through a weak spot in the abdominal wall. If a loop of the intestine becomes trapped in a hernia (incarcerated hernia), it can lead to an obstruction.
• Tumors: Both cancerous and non-cancerous tumors can grow within the wall of the small intestine or press on it from the outside, narrowing the passageway.
• Strictures: These are narrowings of the intestine, often caused by inflammation from conditions like Crohn's disease or radiation therapy.
• Volvulus: This is a twisting of a segment of the intestine on itself, which can cut off blood supply and block the passage.
• Intussusception: This occurs when one part of the intestine telescopes into an adjacent part, much like a collapsing telescope. It's more common in children but can occur in adults, often due to a polyp or tumor.
• Impacted Feces: While less common in the small intestine, a large, hard mass of stool can sometimes cause a blockage.

Causes of Large Bowel (Colon) Obstruction:

• Cancer: Tumors, particularly colorectal cancer, are the most common cause of large bowel obstruction in adults. The tumor can grow to block the lumen of the colon.
• Diverticulitis: Inflammation and infection of small pouches (diverticula) in the colon can lead to swelling and scarring, which can narrow the colon and cause an obstruction.
• Volvulus: Twisting of the sigmoid colon or cecum can lead to obstruction.
• Fecal Impaction: A large, hard mass of stool that cannot be passed can cause a blockage, especially in older adults or those with chronic constipation.
• Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease can cause chronic inflammation and thickening of the bowel wall, leading to strictures and obstruction.
• Hernias: While less common than in the small intestine, hernias can also cause colonic obstruction.

Symptoms of Bowel Obstruction

Symptoms can vary depending on the location and severity of the obstruction, but common signs include:

• Abdominal pain and cramping, often in waves
• Nausea and vomiting
• Bloating and abdominal distension
• Inability to pass gas or have a bowel movement
• Loss of appetite
• Diarrhea (sometimes, especially with a partial obstruction)

When to Seek Medical Attention

A bowel obstruction is a medical emergency. If you experience sudden, severe abdominal pain, persistent vomiting, bloating, and an inability to pass gas or stool, seek immediate medical attention. Prompt diagnosis and treatment are crucial to prevent serious complications.

Diagnosis and Treatment

Diagnosis typically involves a physical examination, medical history, and imaging tests such as X-rays, CT scans, or ultrasounds. Treatment depends on the cause and severity of the obstruction and may include:

• Bowel Rest: Fasting and intravenous fluids to allow the bowel to rest.
• Nasogastric Tube: A tube inserted through the nose into the stomach to decompress the bowel by removing air and fluid.
• Surgery: Often required to remove the blockage, repair damaged bowel, or bypass the obstruction.

The prognosis for bowel obstruction varies greatly depending on the cause, the speed of diagnosis, and the promptness of treatment. Early intervention significantly improves outcomes and reduces the risk of life-threatening complications.