What Is Intestinal Obstruction

Intestinal obstruction is a relatively rare but potentially serious condition that affects the normal flow of contents through the gastrointestinal tract.  It is the cause of 15% of all emergency room visits for severe abdominal pain worldwide.¹

Intestinal obstruction occurs when there is a blockage in the small or large intestine, preventing the passage of food, fluid, and stool.²  

The goal of this article is to give a concise summary of the different types of intestinal blockage, the signs and symptoms as well as treatment options available.

Overview

Bowel obstruction describes obstructions in the intestines that are  due to an accumulation of food, stomach acids, liquids, and gas. The pressure in the gut rises as the accumulation worsens which can cause a  split or a rupture. Bacteria can also spread within the abdominal cavity by whatever is causing the obstruction.

The degree of the blockage will vary as some people may develop a  complete block, while others may develop a  partial block.

Bowel blockages can occur for various reasons, from infections to postoperative problems.

The majority of bowel blockages require medical attention, with surgery required in approximately 20% of cases.  Medication and bowel rest may be used to treat moderate cases however, if severe blockages are left untreated it may result in an intestine rupture.

Types of intestinal obstruction

Complete obstruction

This is when a  portion of the intestine is completely blocked by a severe intestinal obstruction. This prevents the digestive system from processing food, liquids, or gases. This makes it difficult to pass faeces or gas.

Partial obstruction

This is when some of the intestine is blocked and it is not as serious as a full obstruction. Solids, liquids, and gases will move more slowly through the digestive system as a result, but they won't stop totally.

An incomplete intestinal blockage can result in diarrhoea, bloating, and pain.

Pseudo obstruction

This is when a patient displays symptoms of intestinal blockage but there is no bowel obstruction and is extremely rare. 

Causes of intestinal obstruction

Intestinal obstruction can be split into two categories mechanical (dynamic) obstruction and non-mechanical (adynamic) obstruction

Mechanical or dynamic obstruction

When there is a mechanical obstruction, the opening of the intestine (where the contents flow through)  is physically blocked, and there is an increase in contraction and movement of the intestinal muscles to try and push the contents past the obstruction. 

Factors that contribute to mechanical obstruction include:

Adhesions or scar tissues; After abdominal surgery, scars frequently develop as a result of typical wound healing.³ This accounts for roughly 65-75% of cases.⁴

Hernias; Hernias occur when a part of the intestine pushes through a bone or muscle, examples are inguinal and femoral hernias. Inguinal hernias are the most frequent cause of small bowel obstruction since the intestine pushes through the groin area. 

Non Mechanical or Adynamic Obstruction

The contractions of the big and small intestines occur at the same time. A non-mechanical obstruction can occur if anything

disrupts this simultaneous action.

Non-mechanical bowel blockages can be brought on by:

• Abdominal or pelvic surgery scars
• Electrolyte abnormalities
• Diabetes
• Decreased thyroid hormone
• Hirschsprung's disease
• Parkinson's illness
• Severe sickness or infection 
• General anaesthesia 
• Specific painkillers⁶

Signs and symptoms of intestinal obstruction

Important clinical signs of intestinal obstruction include: 

• Abdominal pain
• Vomiting
• Abdominal distension 
• Constipation
• Bloating
• Nausea²

Vomiting is an early symptom and may be accompanied by a quick loss of fluids in small intestinal obstruction. There is often pronounced (severe) pain and central distension (swelling of the abdomen). Because the colon frequently empties distally (the final stages of the digestive process happen in the lower part of the colon farthest away from its starting point), absolute constipation is a late symptom of small bowel blockage.⁷

Management and treatment for intestinal obstruction

The cause of the obstruction will determine the course of therapy your doctor advises. 

• You might need to consume liquids and no solid foods if the obstruction is minor
• An intestinal decompression could be necessary, and most frequently, a nasogastric tube is used for this
• A bowel rest may also be necessary

If your intestinal obstruction is more complicated, surgery will be required immediately. This might be caused by blood flow issues or a perforation in the gut. If various treatments fail to clear the obstruction, surgery can also be necessary. The two objectives are organ repair and obstruction removal.

Alternatively, for more intrusive surgery, your doctor may insert a thin, flexible tube to keep your intestines open.⁹

Diagnosis of intestinal obstruction

Blood test

A complete blood count should be part of the first investigation to determine the condition of the blood cells.

Urea and electrolyte test is used  to determine the degree of dehydration and renal function, 

To rule out pancreatitis, an amylase test is run.²

Radiography

An abdominal radiography should be part of the first assessment of individuals who exhibit clinical symptoms and indicators of intestinal blockage. If an intestinal perforation has occurred, it can be readily determined by radiography.⁸

If there is any abdominal soreness, an erect chest X-ray should be taken to rule out perforation.²     

Computed tomography (CT) scan

When clinical examination and radiography are insufficient to provide a conclusive diagnosis in individuals with suspected intestinal blockage, additional investigation with a CT scan is required. In certain series, a CT scan may detect high-grade blockage with a sensitivity of up to 90% and has the added advantage of identifying the kind and degree of obstruction in the majority of patients.

Additionally, a CT scan can detect urgent causes of intestinal blockage such as intestinal strangulation or volvulus.

A CT scan has a low utility in individuals with partial blockage while being very sensitive and specific for high-grade obstruction.⁸

Risk factors

A bowel blockage is more likely to develop under certain circumstances, such as:

• Cancer, particularly in the abdomen, 
• Ulcerative colitis and Crohn's disease
• Pelvic or abdominal surgery, 
• Radiation treatment⁶

Complications

Complications include:

• Constipation
• Pain
• Reduced appetite
• Inability to swallow food or liquids
• Fever
• Infection
• Intestinal perforation or tear.⁹

FAQs

How can I prevent intestinal obstruction?

1. Maintain a healthy diet with a good balance of fibre and fluids
2. Eat slowly and chew your meal well to promote proper digestion
3. Be cautious when consuming foods that are difficult to digest or are known to cause blockages

How common is an intestinal obstruction?

Intestinal obstruction is relatively common and can occur in people of all ages. 

When should I see a doctor?

When you see signs like

1. Persistent abdominal pain or cramping
2. Vomiting, particularly if it is recurrent or accompanied by the inability to pass gas or stool
3. Swelling or distention of the abdomen

Summary

When food and faeces cannot pass through the intestines, there is a blockage. It results in discomfort, bloating, and nausea. To clear the obstruction, surgery could be required. Ask a doctor to treat your symptoms.