What Is a Bowel Obstruction?
Key takeaways:
A bowel obstruction is a blockage of the intestines. This prevents food and other contents in the gastrointestinal (GI) tract from moving in the right direction.
Common symptoms of a bowel obstruction are severe abdominal pain, bloating, nausea, and vomiting. A CT scan of the abdomen usually diagnoses it.
Treatment starts with the insertion of a nasogastric tube. This removes extra fluid and air from the GI tract to allow the blockage to get better on its own. But this doesn’t always work. Some bowel obstructions need surgery.
The intestine is a long tube that connects the stomach to the anus. There are two main parts to the intestine. The first is the small bowel, which absorbs nutrients from the food you eat. The second is the large bowel, or colon, that forms stool from the body’s waste.
A bowel obstruction is a blockage in the intestine that stops food or other contents from passing normally through the small or large intestine. And these blockages can be a serious problem. Read on to find out more about the causes of a bowel obstruction, along with symptoms and treatments.
Causes of a bowel obstruction
A bowel obstruction happens when something blocks the normal flow of intestinal contents. And different things — both inside and outside the intestine — can cause this. Some specific causes of a bowel obstruction are:
Adhesions: These are strands of scar tissue that can develop after abdominal surgery. They form as part of the normal healing process. But the bowel can get tangled up in these during the normal digestive process.
Tumors: Masses that grow in the intestine can lead to a blockage in the bowel pathway. Tumors in other organs can also expand and compress the bowel from the outside.
Hernias: These are holes in the wall of the abdomen. The intestine can become blocked if it gets trapped in a hernia.
Volvulus: This is a condition in which the bowel loops and twists on itself. Think of this like a twist in a hose that stops water from flowing through it.
Constipation: In severe cases, stool that gets stuck in the colon can block the path of the bowel. It takes a very significant and prolonged case of constipation to cause a bowel obstruction, so this isn’t very common.
Inflammation: If there’s inflammation in the bowel, it can become narrow or stop pushing contents forward like it normally does. Long-term inflammation can also lead to narrowing of the bowel and cause a bowel obstruction called a “stricture.” Inflammatory bowel disease and radiation therapy for cancer can cause this, too.
Ileus: This is a condition in which the muscles in the bowel wall don’t squeeze the contents forward like they normally do. It’s almost like the muscles are temporarily asleep. This most commonly occurs after abdominal surgery.
Symptoms of a bowel obstruction
Symptoms of a bowel obstruction are usually severe. Sometimes they’re mild in the early stages. But as the condition progresses, symptoms typically become much worse. The symptoms occur when contents don’t get through the bowel and back up behind the blockage. You may experience:
Severe abdominal pain
Nausea and vomiting
Abdominal bloating
Decreased gas and stool
Diagnosis for a bowel obstruction
If your symptoms and physical exam suggest a bowel obstruction, you’ll need imaging tests to check for this condition. Usually this means a CT scan, which is a 3D X-ray of the abdomen. It’s the most accurate test to check for a bowel obstruction and its cause. And if something else is causing your symptoms, there’s a good chance it will catch that, too.
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Sometimes a simple X-ray of the abdomen can show a blockage and diagnose a bowel obstruction. But that’s not usually the case. So most people still need a CT scan.
Treatment for a bowel obstruction
If you have a bowel obstruction, the good news is that there are a range of treatment options. Treatment for all bowel obstructions starts with taking pressure off the obstructed area. This includes:
Gastric decompression: Since the bowel is blocked, any food, fluids, or natural secretions from the GI tract don’t have anywhere to go. A nasogastric tube can help. This is a small tube that a provider inserts into the nose and down into the stomach. Then they connect the tube to a suction device, which sucks out the contents of the stomach and upper intestine. This stops the buildup of pressure at the blockage site. It often immediately relieves nausea, vomiting, and pain.
Bowel rest: It’s important to give the bowel a chance to rest, so it can work on untangling itself. That’s why people with a bowel obstruction are restricted from eating or drinking anything. Like a nasogastric tube, this also helps alleviate any pressure at the blockage point.
Intravenous (IV) fluids: A bowel obstruction often leads to dehydration from vomiting. IV fluids provide hydration and replace the fluid losses.
Antiemetics: These are medications that help relieve nausea and vomiting. Examples include ondansetron (Zofran), metoclopramide (Reglan), or prochlorperazine (Compazine).
In many cases, a bowel obstruction gets better on its own with the above treatments. With rest and time, the bowel often reopens on its own. But that’s not always the case. The severity and cause of the blockage determine how likely a bowel obstruction is to go away with these treatments alone.
Some causes of a bowel obstruction, like adhesions, are more likely to get better on their own with these treatments. Other causes, like hernias or a volvulus, are more likely to need surgery.
Do you need surgery for a bowel obstruction?
If a bowel obstruction doesn’t improve with gastric decompression and bowel rest, it might need surgery to fix it.
Other reasons that bowel obstructions need surgery to fix them are:
Strangulation: A severe bowel obstruction can cut off blood flow to the bowel. This can happen when the bowel gets caught in a hernia. It’s dangerous because it can lead to damage or death of the affected area of the intestine. Surgery can release the intestine before this happens.
Necrosis: Even without strangulation, a bowel obstruction can cut off the blood supply to the intestine. This can cause necrosis — when healthy portions of the intestine die — and lead to life-threatening infection.
Perforation: This is a condition in which a hole forms in the wall of the bowel. Similar to necrosis, it can lead to leakage of stool into the abdomen and life-threatening infection. This condition requires emergent surgery.
Severe obstructions: Surgery may be necessary if there are severe or uncontrollable symptoms. Also, the appearance of a bowel obstruction on a CT scan might suggest that it won’t get better on its own without surgery.
If surgery is necessary, there are a few of different surgeries that providers can perform:
Untwisting of the bowel: Sometimes just repositioning the bowel can fix the issue. For example, if the bowel is stuck in a hernia, a surgeon can take the hernia out of the bowel and repair the hernia.
Partial resection: This is when the surgeon removes a small section of the bowel at the site of the blockage. Then they reconnect the remaining ends of the bowel so that they work normally once they heal.
Ostomy: This is when the surgeon creates a hole in the abdominal wall and redirects an end of the intestine to the hole. Stool empties into a plastic bag that attaches to the abdomen. This may be necessary when there’s a lot of inflammation, or if the surgeon can’t connect the two ends of the intestine. Many times, they can reconnect the intestine at a later time, after the bowel heals.
The bottom line
A bowel obstruction is a serious medical condition because it can lead to life-threatening complications. The symptoms aren’t subtle or easy to ignore. Most people with a bowel obstruction experience severe abdominal pain and nausea. The good news is that the intestine can often unblock itself with time and rest. And many people recover from a bowel obstruction without surgery. But surgery may be unavoidable in certain cases, including when complications develop. So it’s best not to delay medical care if you have symptoms of a bowel obstruction.
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References
Cancer.Net. (2020). Bowel obstruction or intestinal blockage.
Catena, F., et al. (2019). Bowel obstruction: A narrative review for all physicians. World Journal of Emergency Surgery.
MedlinePlus. (2022). Intestinal obstruction.
