Peritonitis Explained: How a Stomach Infection Can Turn Life-Threatening

An abdominal infection can sometimes feel like a minor problem. You may expect a few days of abdominal pain, nausea, vomiting, or diarrhoea before things improve. However, in some cases, an infection inside the abdomen can become far more serious. It can spread quickly and lead to a dangerous condition called peritonitis.

Peritonitis is a medical emergency. Without prompt treatment, it can lead to sepsis, organ failure, and even death. Recognising the warning signs early can make a significant difference.

What Is Peritonitis and Why Is It Dangerous?

Peritonitis is inflammation of the peritoneum, the thin membrane that lines the abdominal cavity and covers many of the abdominal organs. When bacteria, digestive fluids, or infected material leak into this area, the peritoneum becomes inflamed.

The condition often develops suddenly. Severe abdominal pain is usually one of the first symptoms. The pain may spread across the abdomen and become worse with movement, coughing, or touching the affected area. 

Peritonitis is dangerous because the infection can spread rapidly. Bacteria may enter the bloodstream and trigger sepsis, a life-threatening condition in which the body's response to infection can damage its own tissues and organs.

There are different types of peritonitis. 

• Primary peritonitis usually occurs when bacteria infect fluid that has accumulated in the abdomen (ascites), most commonly in people with advanced liver disease. 
• Secondary peritonitis is more common and occurs when an organ within the abdomen leaks or ruptures. 

This can result from a ruptured appendix, a perforated stomach ulcer, diverticulitis, bowel perforation, or other gastrointestinal conditions.

• Doctors may describe peritonitis based on its severity and extent of spread. 
• Initially, the infection may remain localised within part of the abdominal cavity. 
• Without treatment, it can spread throughout the body and lead to sepsis or septic shock.

How an Abdominal Infection Can Lead to Peritonitis

Certain severe abdominal infections and conditions that cause a perforation or leak in the digestive tract can lead to peritonitis.

Under normal circumstances, the digestive system keeps bacteria safely contained within the stomach and intestines. However, when an infection, injury, or disease damages the wall of an organ, bacteria and digestive contents can escape into the abdominal cavity. A ruptured appendix is a common example. 

A perforated stomach ulcer can also allow stomach acid and bacteria to leak into the abdomen. Conditions such as diverticulitis, bowel perforation, abdominal trauma, and severe pancreatitis may also contribute to the development of peritonitis.

Sometimes people dismiss abdominal infection symptoms because they believe they have food poisoning or a simple stomach bug. However, worsening pain, abdominal swelling, or fever may indicate that the infection is spreading.

People with liver disease are also at increased risk. Fluid can accumulate in the abdomen, creating an environment where bacteria can multiply. This may lead to spontaneous bacterial peritonitis, a serious condition that requires urgent medical attention.

Symptoms and Causes of Peritonitis

Many mild gastrointestinal infections improve on their own. However, some symptoms should never be ignored.

Common abdominal infection symptoms include:

• Nausea and vomiting
• Diarrhoea
• Abdominal cramps
• Fever
• Loss of appetite
• Bloating

If peritonitis develops, symptoms usually become much more severe.

Common symptoms of peritonitis include:

• Sudden, severe abdominal pain
• A hard, swollen, or distended abdomen
• Pain that worsens with movement
• Fever and chills
• Rapid heartbeat
• Reduced urine output
• Nausea and vomiting
• Extreme weakness or fatigue
• Confusion or dizziness

One of the most important clinical signs of peritonitis is abdominal tenderness. Even light pressure on the abdomen may cause significant pain.

In severe cases, people may experience difficulty breathing or feel faint. These symptoms may indicate that the infection is affecting the entire body and require immediate medical attention.

How Doctors Diagnose Peritonitis Quickly

Doctors treat suspected peritonitis as a medical emergency. Prompt diagnosis is essential because delays can significantly increase the risk of complications.

• The first step is usually a physical examination. Doctors will gently examine the abdomen for swelling, tenderness, rigidity, and signs of irritation.
• Blood tests are commonly used to look for infection and inflammation. An elevated white blood cell count may indicate that the body is fighting a serious infection.
• Imaging tests such as CT scans and ultrasound scans help identify the source of the problem. These tests can reveal fluid collections, inflammation, perforations, or damage within the abdomen.

In some cases, doctors may remove a sample of abdominal fluid through a procedure known as paracentesis. The fluid is then analysed to determine whether bacteria are present. Because the condition can worsen rapidly, treatment often begins before all test results are available.

Emergency Treatment Options for Peritonitis

Treatment for peritonitis usually begins immediately in hospital.

The primary goal is to control the infection. 

• Doctors typically administer intravenous broad-spectrum antibiotics to stop bacteria from spreading further.
• Patients may also receive intravenous fluids to prevent dehydration and maintain blood pressure. 
• Pain relief, oxygen therapy, and other supportive treatments may be required depending on the severity of the illness.

In many cases, surgery is necessary. 

• If a burst appendix, perforated ulcer, bowel perforation, or another abdominal condition has caused the infection, surgeons may need to repair the problem urgently.
• Surgery may also be performed to remove infected material or drain fluid from the abdomen. Eliminating the source of infection is crucial for reducing the risk of sepsis and organ failure.
• Some patients require treatment in an intensive care unit, particularly if the infection has spread to the bloodstream or caused septic shock.
• Recovery depends largely on how quickly treatment begins. Many people recover well when diagnosed and treated early. However, delays can increase the risk of serious complications and prolonged recovery.

When to Seek Immediate Medical Help for Severe Abdominal Pain

Severe abdominal pain should never be ignored, especially when it develops suddenly. You should seek urgent medical attention if you experience:

• Severe abdominal pain that continues to worsen
• A swollen or hard abdomen
• Fever accompanied by abdominal pain
• Persistent vomiting
• Difficulty breathing
• Fainting or confusion
• Blood in vomit or stools

These symptoms may indicate peritonitis or another serious abdominal emergency.

Children, older adults, and people with weakened immune systems may become seriously unwell more quickly. It is always safer to seek medical advice early rather than wait for symptoms to improve.

Final Thoughts

Peritonitis is a serious condition that requires immediate medical attention. What may begin as an abdominal infection can quickly become life-threatening if bacteria spread into the peritoneal cavity and infect the peritoneum.

Recognising the warning signs can save lives. Severe abdominal pain, abdominal swelling, fever, and worsening infection symptoms should never be ignored.

Prompt diagnosis and emergency treatment greatly improve the chances of recovery. If you or someone around you develops signs of peritonitis, seek urgent medical care immediately.

FAQs

Is peritonitis life-threatening?

Yes. Peritonitis is a medical emergency that can lead to sepsis, organ failure, and death if not treated promptly.

Can appendicitis lead to peritonitis?

Yes. A burst appendix can release bacteria into the abdominal cavity and cause peritonitis.

Can peritonitis occur without a fever?

Yes. Some people, particularly older adults and those with weakened immune systems, may not develop a fever despite having peritonitis.

Is surgery always required for peritonitis?

Not always. Surgery is commonly required for secondary peritonitis caused by a rupture, perforation, or internal leak. However, some forms of peritonitis, such as spontaneous bacterial peritonitis, may be treated primarily with antibiotics.

Who is at higher risk of developing peritonitis?

People with liver cirrhosis and ascites, abdominal infections, weakened immune systems, kidney failure, or those undergoing peritoneal dialysis are at increased risk of developing peritonitis.