Peritonitis: Severe pain in the abdomen

In the case of peritonitis, the peritoneum becomes inflamed. This usually triggers severe abdominal pain. You can find out everything about symptoms, diagnosis and therapy here

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Construction inflammation - briefly explained

The peritoneum lines the abdominal cavity. Inflammation of the peritoneum (peritonitis) usually occurs due to a bacterial infection or physical / chemical stimuli such as bleeding, pancreatic secretions or bile. Peritonitis leads to severe abdominal pain with a board-hard abdominal wall. If necessary, there are other symptoms such as fever, nausea, vomiting and even the development of circulatory shock.

Peritonitis is diagnosed through a physical examination, laboratory tests and imaging procedures (sonography, CT, MRI). Treatment depends on the cause. If bacteria are the trigger, antibiotic therapy takes place. If peritonitis was caused by other causes (e.g. gastric perforation, rupture of the gallbladder), this cause must be treated. Surgical procedures, irrigation and drainage systems are used for this. Often, intensive medical monitoring is necessary.

What is peritonitis?

The peritoneum lines the abdominal cavity. It consists of two layers (visceral and parietal sheet). The parietal sheet lies against the abdominal wall and the visceral sheet surrounds the (intraparietal) organs. Inflammation (-itis) of the peritoneum is caused either by microorganisms (mostly bacteria) or physical / chemical stimuli. The peritoneum reacts to the inflammation by exuding a fibrin-containing liquid, which causes adhesions between the abdominal organs. This allows the inflammation to be limited to a small part of the abdominal cavity (local peritonitis). If this does not take place, the inflammation spreads rapidly throughout the abdominal cavity (diffuse / generalized peritonitis).

Peritonitis is a dangerous, untreated life-threatening disease that usually requires intensive medical treatment (surgery, antibiotics, infusions). With the local form, the chances of recovery are often good, but especially with diffuse peritonitis there is a high mortality rate, as it can often lead to blood poisoning (sepsis) with organ damage.

Classification of peritonitis

According to the type of origin (pathogenesis)

  • Primary peritonitis, spontaneous bacterial peritonitis

Primary peritonitis develops due to a hematogenic (bloodstream) or lymphogenic (lymphatic) bacterial invasion of the abdominal cavity. It usually occurs with pre-existing cirrhosis of the liver or ascites. The spread of the pathogen via the bloodstream (hematogenous) with infection of the peritoneum is possible in tuberculosis, for example.

  • Secondary peritonitis, secondary bacterial peritonitis

In secondary peritonitis, the cause is found in the abdomen. At 95 percent, this is the most common form of peritonitis. Due to tears (perforations) in the intestinal area - such as appendicitis (perforated appendicitis) or bursting of a sigmoid diverticulum (perforated sigmoid diverticulitis) - there is a direct colonization of germs in the abdominal cavity due to the intestinal bacteria present. Even with an intestinal obstruction (ileus), bacteria can migrate through the intestinal wall and thus cause peritonitis. In general, a perforation of the hollow organ (breakthrough in the stomach or intestines), if left untreated, leads to peritonitis. Secondary infections can also be found after operations (postoperatively), for example when an intestinal suture opens again (anastomotic leakage). A direct entry of germs is possible with open injuries to the abdominal cavity (puncture injury).

According to the type of expansion

  • Local

With local (spatially limited) peritonitis, only a certain part of the abdominal cavity is affected. For example, local inflammation around a ruptured appendix (perforated appendicitis) can develop.

  • Generalized

Here the inflammation affects the entire abdominal cavity

According to the severity of the general reaction

  • Without organ failure

With a localized extension, there is usually no organ failure

  • With organ failure

The cause is always generalized peritonitis. Organ failure occurs as part of sepsis - blood poisoning. The bacteria and their toxins are washed into the bloodstream via the lymphatic system and distributed throughout the body. Sepsis is a life-threatening condition and always requires intensive therapy.

Causes: what causes peritonitis?

Peritonitis occurs as a complication of other diseases. In the vast majority of cases, it is caused by infections when bacteria or inflammation-promoting substances get into the abdominal cavity via damaged internal organs. Peritonitis occurs more rarely through tumors, through the transmission of germs during operations or after an injury to the abdominal wall or internal organs.

Bacterial infections: Most often, inflammation of the peritoneum occurs as a result of an infection with intestinal bacteria, usually coli bacteria (Escherichia coli) or enterococci. The bacteria are usually released from an organ when, for example, ulcers in the stomach, small intestine, large intestine break through the walls of the affected organ (example: breakthrough in appendicitis). The rupture of a liver or abdominal wall abscess or an inflamed gallbladder also carries the risk of peritonitis. In some cases, bacteria also migrate through a damaged intestinal wall into the abdominal cavity; it comes to so-called peritonitis.

Especially in women, the peritoneum of the small pelvis can become inflamed (pelveoperitonitis) when bacterial pathogens such as chlamydia or gonococci get into the abdominal cavity. This can happen as a result of inflammation of the genital organs.

Bacteria can also be introduced via the bloodstream (hematogenous) and cause inflammation of the peritoneum. However, this form is rare and mainly affects children.

A spontaneous bacterial peritonitis occurs especially with existing liver cirrhosis and accompanying ascites. The cause here is not one of the abovementioned damage to abdominal organs, which requires a different therapy.

Chemically toxic triggers: As a result of organ diseases, foreign substances can get into the abdominal cavity, for example blood, bile from the liver or gallbladder, urine from the bladder, secretions from the pancreas or the contents of cysts. These fluids - or the bacteria they contain - lead to peritonitis or can aggravate existing ones. A special form is the gastric perforation (perforation of an ulcer). The aggressive gastric juice primarily leads to a chemically toxic peritonitis, which, if left untreated, turns into a purulent construction inflammation.

Symptoms: what symptoms does peritonitis cause?

Acute local peritonitis is usually characterized by severe abdominal pain, possibly accompanied by a slight fever. The affected abdominal region hurts when pressed and reacts sensitively with a defensive tension when it is tapped. This classic defense tension cannot be arbitrarily influenced by the patient and is a classic indication of peritonitis. At the same time, constipation or intestinal obstruction can occur.

In diffuse peritonitis, severe abdominal pain in the entire abdominal cavity is the main symptom, combined with a board-hard abdominal wall. The stomach and intestines are disturbed, nausea and vomiting can occur as well as the signs of septic shock: often high fever, cold sweat, accelerated heartbeat, low blood pressure and breathing disorders. An increasing clouding of consciousness can also be an indication of peritonitis.

Caution: The symptoms of peritonitis are not always clear. There can also be other diseases behind the complaints mentioned. The diagnosis can only be made by a doctor after a thorough examination.

Diagnosis: how is peritonitis diagnosed?

First, the anamnesis (medical history) takes place, in which valuable information on previous illnesses and the course can be found. This is followed by a physical examination in which, for example, when examining the abdominal wall, attention is paid to local or generalized immune tension. The main reaction is often a disturbed bowel function. Blood pressure, pulse, temperature and general condition of the patient are also assessed. A blood sample will be taken. Here, as part of a blood culture, germs in the blood can be determined and general signs of inflammation such as an increase in CRP or leukocytes in the blood can be determined. In addition, imaging methods such as an ultrasound examination or CT examinations are used. If the findings are unclear, a so-called exploratory laparoscopy (laparoscopy) is often performed.

Therapy: how is peritonitis treated?

Primary peritonitis can be treated conservatively (without surgery) with antibiotic therapy. Intensive care monitoring is often required.

The most important component in the treatment of secondary and, in particular, generalized peritonitis is the treatment of the actual cause (focus remediation).

  • Surgical focus remediation

Diseases that have led to local peritonitis, such as acute appendicitis or gallbladder inflammation, must be eliminated by surgically removing the source of infection.

  • Drainage systems

The aim is to divert the infectious material to the outside. The drainage can be placed with the help of imaging procedures (sonography or CT control) either from the outside through the skin or during the operation.

  • Debridement / irrigation

In the case of generalized peritonitis, fibrin and pus pads as well as dead tissue are surgically removed (debridement) and the abdominal cavity is rinsed extensively with fluid to remove as many bacteria and toxins (endotoxins) as possible.

Depending on the extent, several operations with rinsing of the abdomen are necessary. If possible, the operations are minimally invasive (minimally invasive) as part of a laparoscopy. The spread of germs into the surgical wounds is thus kept as low as possible. In the case of pronounced findings with massive adhesions in the abdominal cavity, however, a conventional (conventional) operation with an abdominal incision is unavoidable.

  • Intensive treatment

Treatment in an intensive care unit is necessary in the case of pronounced peritonitis and the development of blood poisoning.

  • Antibiotic therapy

At the same time, antibiotics are administered in order to reduce the number of germs. Targeted antibiosis can be carried out, particularly after the pathogen that has triggered the disease has been identified.

Dr. Peter Harding

© W & B / private

Our advisory expert:

Dr. Peter Harding is a doctor for general surgery, trauma surgery and visceral surgery. He is chief physician at the clinic for general and visceral surgery, trauma surgery and proctology at the St. Sixtus Hospital in Haltern am See. His professional focus is on hernia surgery, minimally invasive surgery ("keyhole surgery"), tumor diseases of the gastrointestinal tract, liver and pancreas.


  • Runyon B.A., "Spontaneous bacterial peritonitis in adults: Diagnosis", ed. UpToDate. Waltham, MA: UpToDate Inc. (accessed July 23, 2019)
  • Siewert, Chirurgie, 8th edition, pp. 661-664, Springer Verlag

Important NOTE:
This article contains general information only and should not be used for self-diagnosis or self-treatment. He can not substitute a visit at the doctor. Unfortunately, our experts cannot answer individual questions.