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Published on: 2/27/2026

Sudden Abdominal Pain? Why Peritonitis Is Critical & Medically Approved Next Steps

Peritonitis is a medical emergency: sudden, severe abdominal pain with a rigid, tender belly, fever, nausea or vomiting, bloating, or inability to pass gas can signal a life threatening infection that can quickly lead to sepsis. Pain that worsens with movement is a key red flag.

Seek emergency care now for diagnosis, IV antibiotics, and possible surgery, and see the complete guidance below for full symptom lists, causes, who is at higher risk, how doctors diagnose it, prevention, recovery, and the step by step next actions that may change what you should do.

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Explanation

Sudden Abdominal Pain? Why Peritonitis Is Critical & Medically Approved Next Steps

Sudden, severe abdominal pain should never be ignored. While many stomach problems are minor, peritonitis is a serious medical condition that requires urgent attention. Recognizing the warning signs early — and knowing what to do next — can make a life-saving difference.

This guide explains what peritonitis is, why it's dangerous, the symptoms to watch for, and the medically approved steps you should take if you suspect it.


What Is Peritonitis?

Peritonitis is inflammation of the peritoneum, the thin layer of tissue that lines the inside of your abdomen and covers most abdominal organs. This lining protects and supports your organs, including your stomach, liver, and intestines.

When bacteria, fungi, or irritating substances enter this normally sterile space, the body responds with inflammation. Without rapid treatment, the infection can spread into the bloodstream (sepsis), which can become life-threatening.

Peritonitis is always considered a medical emergency.


What Causes Peritonitis?

Peritonitis typically happens when something allows bacteria to enter the abdominal cavity. Common causes include:

  • Appendicitis that bursts
  • Perforated (ruptured) stomach ulcer
  • Diverticulitis with rupture
  • Pancreatitis
  • Abdominal trauma or injury
  • Complications from abdominal surgery
  • Peritoneal dialysis infections
  • Liver disease with fluid buildup (spontaneous bacterial peritonitis)

In many cases, a hole or tear in the digestive tract allows bacteria to leak into the abdominal space. In other cases, infection develops without a visible rupture, especially in people with advanced liver disease.


Key Symptoms of Peritonitis

The symptoms of peritonitis often come on quickly and feel intense. While not everyone experiences all symptoms, common warning signs include:

  • Sudden, severe abdominal pain
  • Abdominal tenderness (pain worsens when touched)
  • A rigid or "board-like" abdomen
  • Fever and chills
  • Nausea or vomiting
  • Bloating or a feeling of fullness
  • Inability to pass gas or have a bowel movement
  • Rapid heartbeat
  • Weakness or confusion (especially in older adults)

A hallmark sign is pain that worsens with movement. Many people instinctively lie very still because even small movements increase discomfort.

If abdominal pain is severe, persistent, or worsening — especially with fever — it is not something to "wait out."


Why Peritonitis Is So Serious

The abdominal cavity contains vital organs and major blood vessels. Once infection spreads in this space, it can rapidly enter the bloodstream.

Without prompt treatment, complications can include:

  • Sepsis (a life-threatening response to infection)
  • Septic shock
  • Organ failure
  • Abscess formation
  • Death

The progression can be fast — sometimes within hours. This is why early medical evaluation is critical.

The good news: with early diagnosis and appropriate treatment, outcomes improve significantly.


Who Is at Higher Risk?

Certain people are more vulnerable to developing peritonitis:

  • Individuals with cirrhosis or advanced liver disease
  • People receiving peritoneal dialysis
  • Anyone with a recent abdominal surgery
  • Those with untreated gastrointestinal conditions
  • Individuals with weakened immune systems

If you fall into one of these groups, it's especially important to take abdominal pain seriously.


How Doctors Diagnose Peritonitis

If you arrive at an emergency department with suspected peritonitis, medical professionals will act quickly.

Diagnosis typically includes:

  • Physical examination (checking for abdominal rigidity and rebound tenderness)
  • Blood tests to look for infection markers
  • Imaging tests such as CT scan or ultrasound
  • Fluid sampling (especially in patients with abdominal fluid buildup)

Doctors are trained to recognize patterns that point toward peritonitis and begin treatment even while confirming the diagnosis.


Medically Approved Treatment for Peritonitis

Treatment depends on the underlying cause, but usually involves:

1. Immediate Hospitalization

Peritonitis cannot be treated at home.

2. Intravenous (IV) Antibiotics

Broad-spectrum antibiotics are started right away to fight infection.

3. Emergency Surgery (if needed)

If there is a rupture, perforation, or abscess, surgery may be required to:

  • Repair the tear
  • Remove infected tissue
  • Drain infected fluid

4. Supportive Care

This may include:

  • IV fluids
  • Pain management
  • Oxygen therapy
  • Monitoring in an intensive care unit (if severe)

The faster treatment begins, the better the chance of avoiding complications.


When Should You Seek Emergency Care?

Call emergency services or go to the nearest emergency department immediately if you experience:

  • Sudden, severe abdominal pain
  • A hard or rigid abdomen
  • Fever with worsening abdominal pain
  • Fainting, weakness, or confusion
  • Pain following recent abdominal surgery

Do not attempt to treat severe abdominal pain at home with over-the-counter medications alone. Pain relievers can mask symptoms and delay proper treatment.

If there is any possibility that the condition could be serious or life-threatening, speak to a doctor immediately.


Not Sure If It's Peritonitis?

Abdominal pain can have many causes — from gas and indigestion to more serious conditions. If you're experiencing concerning symptoms and want to understand whether they could indicate peritonitis, a free AI-powered symptom checker can help you assess your risk level and determine how urgently you should seek medical care.

A symptom checker is not a diagnosis, but it can help you decide how urgently you should seek medical attention.

However, if your pain is severe or rapidly worsening, skip online tools and go directly to emergency care.


Can Peritonitis Be Prevented?

While not all cases are preventable, certain steps can lower risk:

  • Prompt treatment of appendicitis and abdominal infections
  • Careful hygiene during peritoneal dialysis
  • Regular monitoring for people with liver disease
  • Following post-surgical care instructions carefully
  • Seeking early care for worsening abdominal pain

Prevention often comes down to recognizing symptoms early and acting quickly.


Recovery and Outlook

Recovery depends on:

  • How quickly treatment began
  • The cause of the infection
  • The patient's overall health
  • Whether complications occurred

With rapid treatment, many people recover well. Delays increase the risk of complications.

If you have been treated for peritonitis, follow all discharge instructions carefully and attend follow-up appointments. Report any recurring fever, abdominal pain, or weakness immediately.


The Bottom Line

Peritonitis is a medical emergency. Sudden, severe abdominal pain — especially with fever or abdominal rigidity — should never be ignored.

While not every stomach ache is serious, peritonitis progresses quickly and can become life-threatening without prompt treatment. Acting early can significantly improve outcomes.

If you are unsure about your symptoms, consider a free online symptom check for Peritonitis. But if pain is intense, worsening, or accompanied by fever or weakness, seek emergency care immediately.

Most importantly, if you think your condition could be serious or life-threatening, speak to a doctor right away. Early medical evaluation is always the safest choice.

Your health — and your life — are worth immediate attention.

(References)

  • * Kujath P, Kujath C. Peritonitis: Update on Pathophysiology, Clinical Manifestations, and Management. J Clin Med. 2022 Mar 15;11(6):1618. doi: 10.3390/jcm11061618. PMID: 35329813; PMCID: PMC8945761.

  • * Boermeester MA, Wietasch G. The acute abdomen: a review of the current perspectives. BMC Surg. 2021 May 18;21(1):234. doi: 10.1186/s12893-021-01188-4. PMID: 34005051; PMCID: PMC8130833.

  • * Sartelli M, Coccolini F, Kluger Y, et al. Management of intra-abdominal infections: guidelines of the World Society of Emergency Surgery (WSES). World J Emerg Surg. 2021 Dec 22;16(1):63. doi: 10.1186/s13017-021-00406-8. PMID: 34937516; PMCID: PMC8752814.

  • * Irani M, Irani F, Irani A, et al. Peritonitis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 28613483.

  • * Cui Z, Zhang Z, He H, et al. Surgical management of secondary peritonitis: from principles to practice. Ann Transl Med. 2022 Mar;10(5):324. doi: 10.21037/atm-2022-15. PMID: 35463402; PMCID: PMC9031070.

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