A bowel obstruction is a blockage in the small or the large intestine. It can happen for many reasons, and can lead to severe complications. Dietary measures can help manage symptoms while waiting for treatment or a resolution.

In this article, we examine the symptoms and causes of bowel obstruction. We also look at how doctors can treat this condition and what people can do to prevent it from occurring.

An illustration showing common causes of bowel obstruction.Share on Pinterest
Illustrated by Jason Hoffman

The term bowel obstruction refers to blockages in the intestines that are not the result of fecal matter. Common causes include:

  • twisting of the intestines
  • a hernia
  • inflammation
  • tumors
  • adhesions, or scar tissue, from surgery

Obstructions result in a buildup of food, gastric acids, gas, and fluids. As these continue to accumulate, pressure in the bowel increases. This can result in a rupture or split. Whatever was behind the blockage can enter the abdominal cavity and spread bacteria.

Bowel obstructions can vary in severity. Some only partially obstruct the intestines, while others cause complete blockages.

Most bowel obstructions require treatment. Medication and bowel rest may treat mild cases, while surgery is necessary in around 20% of cases. Severe obstructions may eventually cause an intestinal rupture without treatment.

Types of bowel obstructions

Bowel obstructions can vary depending on the severity of the blockage:

  • Complete obstructions: Severe bowel obstruction can entirely block part of the intestine. This may stop all solids, liquids, and gases from passing through the digestive system. Someone with a complete obstruction will find passing a stool or gas difficult, if not impossible.
  • Partial obstructions: A partial bowel obstruction is typically less severe. These obstructions block some, but not all, of the intestine. This will slow the progress of solids, liquids, and gases through the digestive system but will not stop them entirely. A partial bowel obstruction may cause discomfort, bloating, and diarrhea.
  • Pseudo-obstruction: Intestinal pseudo-obstruction is a rare condition that causes the symptoms of bowel obstruction without the presence of a blockage. It occurs when muscle or nerve issues prevent the normal movement of food, liquids, and gas through the intestines.

Bowel obstructions can be painful and distressing. Symptoms include:

Vomiting and diarrhea are early signs of bowel obstruction. Recognizing these symptoms means that a person can seek treatment before the condition progresses.

If a fever develops after some of these symptoms, it can be a sign of an infection, and a person should consult a doctor.

There are many possible causes of bowel obstruction. They are either mechanical or nonmechanical.

Mechanical obstructions

Mechanical obstructions are physical barriers that prevent or restrict the flow of matter through the bowels. These include:

Nonmechanical obstructions

The large and small bowels move in coordinated contractions. If something interrupts this process, a nonmechanical obstruction can occur.

If a doctor can detect and treat the cause, bowel obstruction is usually a short-term issue.

Some people refer to nonmechanical obstructions as adynamic or paralytic ileus.

Causes of nonmechanical bowel obstructions include:

Some conditions and events increase the risk of a bowel obstruction occurring, such as:

Bowel obstructions and age

People of any age may experience full or partial bowel obstructions. However, obstructions can carry additional complications in younger children and older adults.

Bowel obstructions are a common reason for intensive care admission in newborns. Abnormal formation of the intestines can often cause obstruction in younger children. For example, intussusception is most common in babies aged under 2 years.

Small bowel obstructions are also a common emergency condition in older adults. Obstructions due to malignant tumors are more common in this population as well. The higher prevalence of additional health complications in older adults can alter treatment programs for bowel obstructions.

If severe abdominal pain develops, a person should contact a doctor immediately.

Bowel obstruction can have serious consequences. An individual should seek medical advice if they experience any symptoms of a bowel obstruction.

Diagnosis tends to begin with a physical examination. An obstruction can cause a hard lump in the abdomen, which a doctor may be able to feel. The doctor will also assess a person’s medical history during the initial examination.

A doctor can use a stethoscope to check a person’s bowel activity. A lack of regular bowel sounds or unusually quiet sounds can suggest a bowel obstruction.

Depending on individual cases, a doctor may recommend further tests. These can include:

  • blood tests to check levels of electrolytes, liver and kidney function, and blood counts
  • endoscopy, in which a doctor uses a special camera to look inside the gut
  • CT scans
  • X-rays
  • contrast enemas

Treatment for bowel obstruction depends on the cause and how severe the blockage is.

A total mechanical obstruction usually requires surgery. Most cases of bowel obstruction need some form of medical intervention.

Treatment options for bowel obstruction can include:

  • Medication: Opioids can lead to constipation. If this occurs, laxatives and stool softeners can help.
  • Observation: Doctors will typically observe a person with partial or complete obstructions before considering further options, such as surgery. During this time, the individual should limit their food and drink intake to stop further buildup. Doctors can provide fluid intravenously, meaning directly into the vein, to keep the person hydrated.
  • Nasogastric tube: This is a narrow tube that goes up the nose and into the stomach. It removes fluid and gas trapped in the stomach, relieving pressure. This eases pain and vomiting.
  • Surgery: Surgeons can remove blocked or damaged sections of the bowel. In cases of IBDs, a strictureplasty may be necessary. Here, a surgeon will widen the narrowed section of the bowel by cutting and sewing.
  • Therapeutic enema: A nurse or doctor will push a medication or tap water into the bowel to try to relieve stool impaction, which can happen in severe constipation.

Medication may help ease discomfort due to a bowel obstruction. This can include:

  • antinausea medicines to prevent vomiting
  • pain relief medication
  • antibiotics to fight bacterial infection

People should try to move around when possible and remain hydrated to ensure their electrolytes are balanced.

Those with Crohn’s disease may benefit from steroids.

A bowel obstruction can lead to other issues, such as:

People who have had surgery for obstructions are also at risk of other complications, including:

At worst, it can lead to multiple organ failure and death. That is why it is important to treat bowel obstructions as soon as possible.

Simple changes to a person’s diet and lifestyle can help them digest food more easily and lower the impact of bowel obstructions.

To help prevent bowel obstruction, a person can aim to:

  • drink plenty of water to remain hydrated
  • exercise regularly
  • chew their foods well
  • eat smaller meals throughout the day

If a person is at risk of bowel obstruction, a doctor may recommend avoiding foods that are high in dietary fiber. Reducing the fiber content in a person’s diet aims to reduce the amount of stool and reduce how often a person may need to empty their bowels.

The following table outlines some foods to eat:

Carbohydrateswhite bread
white rice
white pasta
white flour
low fiber breakfast cereals
Fruitcanned peaches and pears
peeled and cored apples
fruit juice, excluding orange juice
Vegetablespotatoes without the skin
well cooked squash, carrots, courgette, asparagus, and beetroot
ProteinAll meant and fish
yogurt without fruit

A bowel obstruction occurs when something blocks part of the small or the large intestine. It is vital to take this condition seriously and seek immediate medical attention.

Tumors, scar tissue from surgery, and abnormalities in a person’s intestinal development can all cause bowel obstructions.

Bowel obstructions can lead to severe complications. In extreme cases, they can cause intestinal ruptures and be deadly if a person does not receive timely treatment.

Individuals can lower their risk of developing an obstruction by eating well, keeping active, and staying hydrated.

The outlook for a bowel obstruction depends on its cause. In most cases, bowel obstruction is treatable.

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