Peritonitis: Symptoms, Types, Causes and Treatment

Peritonitis is a serious and potentially life-threatening inflammation of the peritoneum, the thin tissue lining the inside of the abdomen and covering abdominal organs. Understanding its symptoms, various types, underlying causes, and treatment approaches is crucial for early recognition and effective management. This article synthesizes current research to provide a comprehensive overview of peritonitis, equipping readers—whether patients, caregivers, or healthcare professionals—with evidence-based insights.

Symptoms of Peritonitis

Recognizing peritonitis early is critical, as prompt intervention can significantly impact outcomes. Symptoms often develop suddenly and can be severe, but may vary depending on the underlying cause and patient condition.

Symptom	Description	Patient Groups Affected	Source
Abdominal pain	Severe, persistent pain, often worsens with movement	All patients	1,2,6,8
Fever	Elevated body temperature	Common in all presentations	1,2,6,8
Nausea/Vomiting	Feeling sick, may vomit	Frequently seen	1,2,8
Abdominal distension	Swelling of the abdomen	Secondary peritonitis, severe cases	2,8
Guarding/Rigidity	Involuntary tensing of abdominal muscles	Typical in generalized peritonitis	2,8
Altered mental status	Confusion, disorientation	Especially in cirrhosis/SBP	1,5
Diarrhea	Loose stools	Some cases, especially primary	1

Table 1: Key Symptoms

Recognizing the Warning Signs

Abdominal Pain and Tenderness

Severe abdominal pain is the hallmark symptom of peritonitis. Patients often describe it as constant, sharp, or aching, and it typically worsens with movement or touch. In cases of generalized secondary peritonitis, pain may be diffuse and accompanied by abdominal guarding or rigidity—a sign that the body is trying to protect the inflamed area 2,8.

Systemic Symptoms: Fever, Nausea, Vomiting

Fever is almost always present, signaling the body’s response to infection or inflammation. Nausea and vomiting frequently occur, as the digestive system is disrupted by the underlying pathology 1,2,6.

Abdominal Distension and Bowel Changes

Abdominal swelling or distension is particularly common in cases involving bowel perforation or severe infection. Diarrhea may also be present, especially in primary peritonitis or spontaneous bacterial peritonitis (SBP) 1,8.

Altered Mental Status

In patients with advanced liver disease or cirrhosis, peritonitis may present with confusion or altered consciousness. This is especially true in SBP, as toxins build up in the bloodstream due to liver dysfunction 1,5.

Special Populations: Peritoneal Dialysis Patients

For patients on peritoneal dialysis, cloudy dialysis fluid, abdominal pain, and sometimes fever or malaise may be the first signs of peritonitis 7,14.

Types of Peritonitis

Peritonitis can be classified into several distinct types based on its origin, underlying cause, and patient population. Each type has unique features, risk factors, and management considerations.

Type	Defining Feature	Typical Patient Group	Source
Primary (Spontaneous)	Infection without intra-abdominal source	Cirrhotic patients with ascites	1,4,5
Secondary	Due to perforation or intra-abdominal event	All ages, surgical patients	2,6,8
Tertiary	Persistent/recurrent despite treatment	Critically ill, nosocomial	1
Dialysis-associated	Related to peritoneal dialysis (PD)	Patients on PD	7,14
Fungal	Infection by fungi (e.g., Candida)	PD patients, immunosuppressed	13
Tuberculous	Caused by Mycobacterium tuberculosis	Immunosuppressed, endemic areas	3

Table 2: Types of Peritonitis

Primary (Spontaneous) Peritonitis

This form, often called spontaneous bacterial peritonitis (SBP), occurs without an obvious intra-abdominal source of infection. It is most common in patients with liver cirrhosis and ascites, due to impaired immune defenses and bacterial translocation from the gut 1,4,5.

Secondary Peritonitis

Secondary peritonitis arises from a clear intra-abdominal source, such as a perforated ulcer, ruptured appendix, or bowel injury. It is the most frequent and severe type, requiring urgent surgical intervention 2,6,8.

Tertiary Peritonitis

Tertiary peritonitis is a persistent or recurrent infection that continues despite initial surgical and medical therapy. It is often seen in critically ill or immunocompromised patients, and may involve multidrug-resistant organisms 1,12.

Peritoneal Dialysis-Associated Peritonitis

Patients on peritoneal dialysis are at risk for infection due to repeated access of the peritoneal cavity. These infections can be bacterial or, less commonly, fungal, and may threaten the viability of dialysis 7,14,13.

Fungal and Tuberculous Peritonitis

Fungal peritonitis is rare but serious, often occurring as a complication of previous antibiotic use or in immunosuppressed patients. Tuberculous peritonitis, though uncommon in developed countries, is seen in high-risk populations and requires specific diagnostic and therapeutic approaches 3,13.

Causes of Peritonitis

The underlying causes of peritonitis are diverse, ranging from infections to chemical irritants, with some causes more prevalent in specific populations or regions.

Cause	Examples or Mechanisms	Risk Groups / Notes	Source
Bacterial infection	E. coli, Klebsiella, Streptococci	Most common cause, especially SBP	4,5,12
Hollow viscus perforation	Peptic ulcer, appendicitis, diverticulitis	Leading cause of secondary peritonitis	2,6,8
Fungal infection	Candida spp., other yeasts	PD patients, immunosuppressed	13
Tuberculosis	M. tuberculosis infection	HIV, cirrhosis, endemic areas	3
Chemical irritants	Bile, gastric acid, urine, foreign bodies	Trauma, surgery, leaks	6,10
Peritoneal dialysis	Catheter contamination	Dialysis patients	7,14

Table 3: Causes of Peritonitis

Infectious Causes

Bacterial Infections

• The majority of peritonitis cases are caused by bacteria, especially Gram-negative bacilli such as Escherichia coli and Klebsiella pneumoniae. Gram-positive organisms, including Streptococcus and Staphylococcus species, are also implicated, particularly in peritoneal dialysis-associated infections 4,5,12.
• In SBP, bacteria translocate from the gut into the ascitic fluid due to increased intestinal permeability and immune dysfunction in cirrhosis 4,5.

Fungal Infections

• Fungal peritonitis, most frequently caused by Candida species, is a rare but severe complication, primarily seen in patients on peritoneal dialysis or with prior broad-spectrum antibiotic use 13.

Tuberculous Peritonitis

• Caused by Mycobacterium tuberculosis, this form is more common in regions with high TB prevalence or among immunosuppressed patients, such as those with HIV/AIDS or cirrhosis. Diagnosis can be challenging, often requiring peritoneal biopsy 3.

Non-Infectious Causes

Hollow Viscus Perforation

• Secondary peritonitis frequently results from a perforated organ within the abdomen, such as a peptic ulcer, appendix, or intestine. The leakage of gastrointestinal contents into the peritoneal cavity rapidly triggers inflammation and infection 2,6,8.

Chemical Irritation

• Leakage of sterile bodily fluids—such as bile, blood, urine, or gastric acid—into the peritoneal cavity following trauma or surgery can also incite peritonitis, even in the absence of infection 6,10.

Peritoneal Dialysis

• Repeated access and manipulation of the peritoneal cavity during dialysis increase the risk of infection, particularly if aseptic technique is not strictly followed 7,14.

Treatment of Peritonitis

Effective management of peritonitis is time-sensitive and multifaceted, involving supportive care, antimicrobial therapy, and often surgical intervention. The approach varies depending on the type and severity of peritonitis, underlying cause, and patient condition.

Treatment	Approach/Agent/Procedure	Key Considerations	Source
Supportive care	Fluids, electrolytes, pain management	Stabilize patient, correct imbalances	1,12,15
Antibiotics	Broad-spectrum, tailored to pathogens	Early initiation critical; adjust per etiology	1,5,12,15
Surgery	Source control, repair perforation	Essential for secondary peritonitis	2,6,11,15
Peritoneal dialysis peritonitis	Intraperitoneal antibiotics, catheter removal	Catheter removal for refractory cases	7,13,14
Fungal peritonitis	Antifungal drugs, catheter removal	Fluconazole, amphotericin B, voriconazole	13
Albumin infusion	Adjunct in SBP with renal impairment	Reduces risk of kidney failure	5

Table 4: Treatment Approaches

General Principles

Supportive Management

Immediate stabilization with intravenous fluids, correction of electrolyte disturbances, pain control, and monitoring of vital signs are the first steps in all cases 1,12.

Antimicrobial Therapy

• Prompt initiation is crucial: Delays in starting antibiotics can sharply increase mortality, especially in septic shock 1.
• Empiric therapy: Broad-spectrum antibiotics targeting both Gram-negative and Gram-positive organisms, as well as anaerobes, are typically started while awaiting culture results 5,12,15.
• Tailoring therapy: Once the specific pathogen is identified, therapy should be narrowed to target the causative organism and local resistance patterns 5.

Surgical Intervention

• Source control: In secondary peritonitis, surgery is often needed to repair the perforated organ, remove infected tissue, or drain abscesses 2,6,11.
• Techniques: Approaches may include laparotomy (open surgery) or laparoscopy (minimally invasive), with procedures such as omental patch repair for peptic ulcer perforation 2,8,15.
• Aggressive management: Severe cases may require repeated surgeries or damage control techniques to manage persistent infection and prevent organ failure 11,12.

Special Considerations

Peritoneal Dialysis-Associated Peritonitis

• Intraperitoneal antibiotics: Direct delivery into the peritoneal cavity is preferred and more effective than intravenous administration for PD-related infections 14.
• Catheter management: Persistent or relapsing infections often necessitate removal (and possibly replacement) of the dialysis catheter 7,13,14.

Fungal Peritonitis

• Antifungal agents: Fluconazole, amphotericin B, and newer drugs such as voriconazole are mainstays of therapy 13.
• Early catheter removal: Especially in PD patients, removal of the peritoneal dialysis catheter is strongly recommended for effective treatment 13.

Tuberculous Peritonitis

• Anti-TB therapy: Standard regimens are effective in most cases, with surgery reserved for complications such as bowel perforation or obstruction 3.

Adjuncts and Preventive Strategies

• Albumin infusion: Especially in SBP patients with kidney dysfunction, albumin reduces the risk of renal failure and mortality 5.
• Antibiotic prophylaxis: In high-risk patients, selective use of antibiotics can prevent recurrence of SBP 5.
• Supportive care: Includes nutritional support, monitoring for complications, and intensive care for critically ill patients 12.

Conclusion

Peritonitis remains a major medical emergency with high risk for severe complications and death if not promptly recognized and treated. Its diverse causes and presentations require tailored diagnostic and therapeutic strategies. Early intervention, combining supportive care, targeted antimicrobial therapy, and—when necessary—surgical management, is essential for optimal outcomes.

Main Points Covered:

• Peritonitis presents with severe abdominal pain, fever, and other systemic symptoms; early recognition is vital 1,2,8.
• Major types include primary (SBP), secondary, tertiary, dialysis-associated, fungal, and tuberculous peritonitis, each with distinct features 1,2,3,7,13.
• Causes range from bacterial and fungal infections to hollow viscus perforation, chemical irritation, and tuberculosis 2,4,5,6,8,13.
• Treatment requires supportive care, prompt and targeted antibiotics, surgical intervention for secondary cases, and specific management for special populations such as PD patients or those with fungal or tuberculous peritonitis 1,5,11,12,13,14,15.
• Ongoing research and clinical vigilance are needed for early diagnosis, improved therapies, and better outcomes for all patients with peritonitis.