Peritonitis: symptoms, causes, treatment and when it becomes life threatening

Peritonitis is a serious inflammation or infection of the peritoneum, the thin layer of tissue that lines the inside of your abdomen and covers many of your abdominal organs. It can develop when bacteria enter the abdominal cavity, when an organ becomes perforated, or in certain medical conditions such as advanced liver disease or peritoneal dialysis.

What makes peritonitis particularly concerning is how quickly it can worsen. A problem that starts with abdominal pain can progress to a severe infection, sepsis, organ failure and, in untreated cases, death. This is why suspected peritonitis should never be ignored.

The good news is that peritonitis can often be successfully treated when it is diagnosed and managed promptly. Treatment depends on what caused it and may include antibiotics, intravenous fluids, drainage procedures or surgery.

What is peritonitis?

The peritoneum is a protective lining inside the abdomen. When this tissue becomes inflamed, the condition is called peritonitis.

Peritonitis may be caused by an infection, leakage of intestinal contents, blood or other body fluids into the abdominal cavity, or inflammation caused by substances that normally remain inside an organ.

Doctors generally describe peritonitis as primary, secondary or tertiary, depending on how it develops and whether the infection persists or returns.

Primary peritonitis usually occurs without an obvious perforation of an abdominal organ. A common example is spontaneous bacterial peritonitis in people with significant ascites, particularly those with advanced liver disease.

Secondary peritonitis is more common and usually occurs because bacteria or other contents escape from a damaged or perforated abdominal organ.

Tertiary peritonitis refers to persistent or recurrent infection after treatment of an earlier episode, usually in people who are seriously ill or have other major health problems.

What are the symptoms of peritonitis?

The symptoms can vary depending on the cause and how advanced the infection has become. However, abdominal pain and tenderness are among the most important warning signs.

Common symptoms include:

• Severe or worsening abdominal pain
• Abdominal tenderness
• A swollen, bloated or tight abdomen
• Fever or chills
• Nausea and vomiting
• Loss of appetite
• Constipation or inability to pass stool or gas
• Reduced urine output
• Excessive thirst
• Rapid heartbeat
• Fatigue or weakness
• Shortness of breath
• Confusion in severe cases

The pain may become worse when you move or when the abdomen is touched. In some people, the abdomen becomes extremely tender and may feel unusually firm or rigid.

For someone undergoing peritoneal dialysis, another important warning sign is cloudy dialysis fluid. The fluid may also contain white flecks, strands or clumps, and there may be pain or redness around the catheter site.

What is one of the first signs of peritonitis?

One of the earliest and most characteristic signs is abdominal pain or tenderness, particularly when the pain is persistent or progressively worsening.

A dull abdominal ache that suddenly becomes sharper and does not settle should be taken seriously. Fever, nausea, vomiting and abdominal swelling may develop alongside the pain.

There is no single symptom that confirms peritonitis. Abdominal pain can occur with many other conditions, so medical assessment is essential.

What causes peritonitis?

Peritonitis has several possible causes, but bacterial infection is one of the most common.

Perforation of an abdominal organ

A hole or rupture in the stomach or intestine can allow bacteria and digestive contents to spill into the abdominal cavity. This can rapidly trigger severe inflammation and infection.

Conditions that may cause perforation include:

• A ruptured appendix
• A perforated stomach ulcer
• A perforated intestine
• Complicated diverticulitis
• Inflammatory bowel disease with intestinal perforation
• Abdominal trauma
• Certain complications after abdominal surgery

Liver disease and ascites

People with advanced liver disease may develop ascites, meaning an abnormal accumulation of fluid in the abdomen. Bacteria can infect this fluid, resulting in spontaneous bacterial peritonitis.

This type does not necessarily require a hole in an abdominal organ.

Peritoneal dialysis

People receiving peritoneal dialysis have a catheter that provides access to the abdominal cavity. If bacteria enter through or around the catheter, peritonitis can develop.

Careful hand hygiene, catheter care and following the dialysis team’s instructions are important ways of reducing this risk.

Other causes

Less common causes include complications from abdominal procedures, severe pancreatitis, gallbladder perforation and certain abdominal injuries. Peritonitis can also occur when substances such as bile, pancreatic enzymes or stomach contents leak into the peritoneal cavity and cause chemical inflammation.

What organ is most likely to cause peritonitis?

There isn’t one single organ responsible for all cases of peritonitis. However, the appendix, stomach and intestines are important sources of secondary peritonitis, particularly when they perforate.

A ruptured appendix is a well-known cause. Perforation of the stomach due to a peptic ulcer and perforation of the intestine due to conditions such as diverticulitis can also allow bacteria and intestinal contents to enter the abdominal cavity.

The underlying cause matters because treating the infection alone may not be enough. If there is a perforated organ, the source of contamination generally needs to be controlled as well.

What are the three stages of peritonitis?

The terms primary, secondary and tertiary peritonitis are sometimes described as the three major clinical categories or stages of peritonitis.

1. Primary peritonitis

Primary peritonitis develops without an obvious perforation or direct injury to an abdominal organ. Spontaneous bacterial peritonitis associated with ascites is an important example.

Peritoneal dialysis-associated infection is another setting in which infection can enter the peritoneal cavity without a perforated bowel.

2. Secondary peritonitis

Secondary peritonitis occurs because another abdominal problem allows bacteria or irritating fluids to enter the peritoneal cavity.

A ruptured appendix, perforated ulcer, perforated bowel, abdominal trauma or postoperative infection may cause this form.

3. Tertiary peritonitis

Tertiary peritonitis refers to an infection that persists or returns after treatment of an earlier episode. It is generally seen in people who are severely ill and may involve resistant organisms or other complicated infections.

These categories are useful for doctors, but they shouldn’t be interpreted as a predictable three-step progression that every patient experiences.

How quickly can peritonitis develop?

Peritonitis can develop very quickly, particularly when it results from a perforated abdominal organ.

For example, if the appendix or intestine ruptures, bacteria and intestinal contents can rapidly contaminate the abdominal cavity. The resulting inflammation and infection can progress to sepsis.

The speed varies according to the cause, the amount of contamination, the person’s immune system and other underlying medical conditions. Someone with significant liver disease or a weakened immune system may also become seriously ill without the classic symptoms being very dramatic at first.

Because of this, severe or rapidly worsening abdominal pain should be evaluated urgently rather than waiting to see whether it settles.

Can you have peritonitis without knowing?

It is possible for peritonitis to begin with relatively subtle symptoms, particularly in people with serious underlying illnesses. However, significant peritonitis generally causes symptoms, and these should not be ignored.

People with spontaneous bacterial peritonitis, for example, may not always have the same dramatic abdominal symptoms seen with a perforated bowel. Fever, weakness, confusion or a general deterioration in health may sometimes be more noticeable.

People on peritoneal dialysis should pay particular attention to changes in dialysis fluid, especially cloudiness or unusual particles.

How do I know if I have peritonitis?

You cannot reliably diagnose peritonitis at home.

If you have persistent or severe abdominal pain, abdominal tenderness, swelling, fever, vomiting, reduced urine output or an inability to pass stool or gas, you should seek urgent medical attention.

Doctors diagnose peritonitis using a combination of your symptoms, physical examination, blood tests and imaging. Depending on the situation, an ultrasound or CT scan may be performed. If fluid has accumulated in the abdomen, a sample may be removed with a needle and tested for infection.

In people undergoing peritoneal dialysis, the dialysis fluid can be tested to look for infection.

How is peritonitis treated?

Treatment needs to begin quickly because untreated peritonitis can progress to sepsis and organ failure.

Treatment may include:

Antibiotics

Broad-spectrum antibiotics are commonly started when bacterial peritonitis is suspected. Once laboratory testing identifies the organism, doctors may adjust the antibiotic to target the specific bacteria more accurately.

Intravenous fluids

IV fluids may be needed to maintain circulation, correct dehydration and reduce the risk of shock, especially when sepsis is present or suspected.

Surgery

If peritonitis is caused by a ruptured appendix, perforated bowel, perforated ulcer or another structural problem, surgery may be necessary to control the source of infection.

In some situations, doctors may use drainage procedures to remove infected fluid or an abscess. The exact approach depends on the underlying cause and the patient’s condition.

Treatment for peritoneal dialysis-related peritonitis

When peritonitis occurs in someone receiving peritoneal dialysis, antibiotics may be administered through the dialysis fluid or by another appropriate route. In persistent or recurrent cases, temporary or permanent changes to the dialysis method may be required.

What antibiotics are used to treat peritonitis?

There is no single antibiotic that is appropriate for every case of peritonitis.

Doctors commonly begin with broad-spectrum antibiotics that cover the bacteria likely to be responsible. Depending on the type of infection and local resistance patterns, medicines such as piperacillin-tazobactam, ceftriaxone or other third-generation cephalosporins combined with an anaerobic-covering antibiotic, or carbapenems such as meropenem may be considered in particular clinical situations.

For spontaneous bacterial peritonitis, antibiotic selection differs from the treatment of complicated secondary peritonitis. Peritoneal dialysis-associated peritonitis also has its own treatment protocols.

The final antibiotic choice depends on the source of infection, severity, kidney and liver function, allergies, previous antibiotic exposure and culture results. Antibiotics should therefore not be self-started or selected without medical advice.

Is peritonitis life threatening?

Yes. Peritonitis can be life threatening.

The major concern is that infection inside the abdomen can spread into the bloodstream and trigger sepsis. Severe sepsis can cause dangerously low blood pressure, organ dysfunction, shock and death.

This does not mean that everyone diagnosed with peritonitis will have a poor outcome. Early diagnosis and appropriate treatment can make a major difference.

Sudden severe abdominal pain, particularly when accompanied by fever, vomiting, abdominal swelling or weakness, warrants urgent medical evaluation.

Can peritonitis be fixed?

Yes. Peritonitis can often be successfully treated, especially when it is recognized early.

However, treatment must address both the infection and its underlying cause. Antibiotics may be sufficient in some forms, while other cases require drainage or emergency surgery.

Recovery depends on how severe the infection was, how quickly treatment started, the person’s general health and whether complications such as sepsis or organ failure occurred.

How long can you live with peritonitis?

There is no safe number of days or weeks that someone can live with untreated peritonitis.

Some cases can deteriorate rapidly, and delaying treatment can allow infection to progress to sepsis, shock and organ failure. The time course depends heavily on the cause and the person’s health.

Therefore, peritonitis should never be watched at home to see how long it takes to improve. If it is suspected, urgent medical assessment is appropriate.

Can a person survive peritonitis?

Yes. Many people do survive peritonitis, particularly when it is diagnosed and treated promptly.

The outcome depends on factors such as the cause of peritonitis, the extent of abdominal contamination, the presence of sepsis, age, underlying diseases and how quickly effective treatment is started.

People who develop complications such as severe sepsis or organ failure are at considerably greater risk.

How can peritonitis be prevented?

Not every case of peritonitis can be prevented because some causes are sudden and unpredictable. However, several measures can reduce the risk.

If you are receiving peritoneal dialysis:

• Wash your hands carefully before handling the catheter.
• Keep the catheter exit site clean.
• Follow your dialysis team’s instructions.
• Keep dialysis supplies in a clean area.
• Use appropriate protective measures during exchanges.
• Report cloudy dialysis fluid or abdominal pain promptly.

These precautions are particularly important because contamination around the catheter can introduce bacteria into the abdominal cavity.

For everyone else, seeking timely treatment for appendicitis, diverticulitis, ulcers and other abdominal conditions can reduce the risk of complications such as perforation and peritonitis.

When should you seek emergency medical care?

Do not wait for all the symptoms to appear.

Seek urgent medical attention if you develop:

• Sudden or severe abdominal pain
• Abdominal pain that keeps getting worse
• A very tender, swollen or rigid abdomen
• Fever with significant abdominal pain
• Persistent vomiting
• Difficulty passing stool or gas
• Very little urine
• Confusion, weakness or severe fatigue
• Rapid heartbeat or breathing difficulty
• Cloudy dialysis fluid if you are receiving peritoneal dialysis

Severe abdominal pain can have many causes, but peritonitis is one of the conditions doctors need to rule out quickly.

Frequently asked questions about peritonitis

What is the first indication of peritonitis?

Persistent abdominal pain or tenderness is often one of the first and most important indications. The pain may worsen with movement or touch and may become progressively more severe. Fever, nausea, vomiting and abdominal swelling can follow.

What are the symptoms of peritonitis?

Common symptoms include abdominal pain and tenderness, abdominal swelling, fever, nausea, vomiting, loss of appetite, constipation, inability to pass gas, reduced urine output, fatigue and, in severe cases, confusion or breathing difficulties.

What causes peritonitis?

Peritonitis can result from bacterial or fungal infection, a ruptured appendix, perforated stomach or intestine, diverticulitis, abdominal trauma, complications after surgery, peritoneal dialysis or spontaneous bacterial infection of ascitic fluid.

Is peritonitis life threatening?

Yes. Untreated peritonitis can lead to sepsis, septic shock, organ failure and death. Prompt medical treatment significantly improves the chances of recovery.

What are the three stages of peritonitis?

The three commonly described categories are primary, secondary and tertiary peritonitis. Primary occurs without an obvious perforation, secondary results from another abdominal source such as a perforated organ, and tertiary refers to persistent or recurrent infection after treatment.

What organ is most likely to cause peritonitis?

There is no single organ responsible for every case. The appendix, stomach and intestines are important sources, particularly when they rupture or perforate.

How is peritonitis treated?

Treatment may involve broad-spectrum antibiotics, IV fluids, supportive care, drainage of infected collections and surgery to repair or remove the underlying source.

Can peritonitis be fixed?

Yes. Many patients recover fully when peritonitis is treated promptly. Recovery depends on the cause, severity and whether complications such as sepsis or organ damage have occurred.

How quickly can peritonitis develop?

It can develop rapidly, particularly following perforation of an abdominal organ. The infection may worsen quickly, which is why severe or rapidly worsening abdominal pain requires urgent assessment.

What antibiotics are used to treat peritonitis?

Doctors may use broad-spectrum antibiotics such as piperacillin-tazobactam, certain cephalosporin-based combinations or carbapenems depending on the type and severity of infection. The exact antibiotic should be selected by a doctor based on the suspected source and, when available, culture results.

Can you have peritonitis without knowing?

Early symptoms can sometimes be subtle, especially in people with serious underlying illnesses. However, peritonitis is usually associated with symptoms such as abdominal pain, tenderness, fever or general deterioration. People on peritoneal dialysis should pay particular attention to cloudy dialysis fluid.

How can I prevent peritonitis?

Good catheter hygiene is particularly important for people on peritoneal dialysis. Prompt treatment of abdominal infections and following medical advice after abdominal procedures can also reduce the risk.

How do I know if I have peritonitis?

You cannot confirm peritonitis based on symptoms alone. Severe or persistent abdominal pain, tenderness, swelling and fever should prompt urgent medical assessment. Doctors may use blood tests, imaging and analysis of abdominal fluid to establish the diagnosis.

How long can you live with peritonitis?

There is no predictable survival time for untreated peritonitis. Some cases can become life threatening quickly, particularly when they lead to sepsis. It should be treated as a medical emergency.

Can a person survive peritonitis?

Yes. With rapid diagnosis and appropriate treatment, many people recover. The prognosis is less favorable when treatment is delayed or when severe sepsis, shock or organ failure develops.

Final thoughts

Peritonitis is one of those conditions where timing matters. Abdominal pain is common and often has a harmless explanation, but severe, persistent or rapidly worsening pain—especially when accompanied by fever, vomiting, swelling or reduced urine—should not be ignored.

Peritonitis can arise from a ruptured appendix, perforated ulcer, bowel problem, abdominal injury, peritoneal dialysis or an infection associated with ascites. Although it can become life threatening, it is often treatable when recognized early.

If you or someone around you has symptoms that could indicate peritonitis, seek urgent medical care rather than trying to manage the condition at home. Early diagnosis, antibiotics when appropriate, supportive treatment and timely control of the underlying cause can significantly improve the chances of recovery.

This article is for general educational purposes and is not a substitute for examination or treatment by a qualified healthcare professional. Suspected peritonitis requires urgent medical evaluation.

If you or a loved one experiences symptoms suggestive of peritonitis, do not delay—seek medical help immediately.

Sparsh Doctor List