Inflamed Abdomen – Causes, Symptoms and Treatment

The abdomen is the portion of the torso that lies between the chest (thorax) and pelvis. It is a large cavity with many different organs, most of which are are part of the digestive system. These organs are tightly packed within the abdominal cavity. A thin layer of tissue lines the organs to cater for movement and friction between the organs and produces lubricate fluid. This lining is known as the peritoneum and the lubricant is known as peritoneal fluid.

What is abdominal inflammation?

An inflamed abdomen is a broad term that could refer to inflammation of specific organs within the abdomen. However, it is often a common term used to refer to peritonitis – inflammation of the peritoneum. The inflammation can occur for various reasons but is most commonly caused by an infection. Abdominal pain, tenderness and distension (ascites) are the more common symptoms to arise with abdominal inflammation.

Peritonitis needs to be treated promptly, especially infectious peritonitis. Complications may arise and can sometimes even be life-threatening if the infection spreads and results in severe conditions like sepsis. This can result in shock and even organ failure.

Causes of Inflamed Abdomen

Infectious peritonitis is by far the most common and most of the time it is due to a bacterial infection. Non-infectious causes lead to sterile peritonitis and is often due to chemical irritation as is the case when digestive enzymes leak out of the guy and into the peritoneal cavity. Sometimes peritonitis arises on its own without any preceding trauma or underlying infection. This is known as spontaeous peritonitis.


Injury to the peritoneum can either be due to mechanical or chemical factors. With regards to mechanical causes, it is usually due to procedures like surgery to the abdomen or peritoneal dialysis. An infection of the peritoneum can also arise. Chemical injury is more likely to be seen with conditions where the digestive enzymes leak into the peritoneal cavity and irritate the peritoneum.


Peritonitis can occur when the an organ ruptures, especially if the wall of any of the digestive organs is compromised. The digestive enzymes can leak out into the peritoneal cavity and irritate the peritoneum. Depending on the organ that ruptures, bacteria and other microbes may also enter the peritoneal cavity and infect the peritoneum. This is more common with a rupture of the lower parts of the gastrointestinal tract, and especially with the appendix and colon.


An infection of the peritoneum is the most common cause of peritonitis. Most cases arise following trauma or with rupture of an organ within the abdominal cavity. Bacterial peritonitis is the more common infection. An intra-peritoneal abscess may form. Sometimes an infection of an organ can also lead to infectious peritonitis when the infection spreads directly. It is also possible for the infection to spread from a distant site through the bloodstream (hematogenous spread).


Blood can also irritate the peritoneum. Any hemorrhage resulting in blood pooling within the peritoneal cavity can therefore lead to peritonitis. Even other fluids within the peritoneal cavity may also be act as irritants. Although there is peritoneal fluid within the cavity, this is usually of a small volume. An increase of fluid like interstitial fluid as is seen with conditions like Budd-Chiari  syndrome and cirrhosis.


Peritonitis can arise as a complication of pancreas inflammation (pancreatitis). This is more commonly seen with acute pancreatitis. The digestive enzymes that are prematurely activated within the pancreas can also irritate the peritoneum. Acute pancreatitis is mainly due to excessive alcohol intake.

Foreign Bodies

A foreign body in the peritoneal cavity is not a common cause of peritonitis but can occur after surgery. Sometimes a foreign body may gain entry into the peritoneal cavity following trauma to the chest wall and subsequent suturing of the wound without proper removal of the object.

Signs and Symptoms

Pain, swelling, heat and redness are the main features of inflammation. With an inflamed abdomen, abdominal pain and abdominal swelling are prominent symptoms. Heat and redness are usually not visible as the peritonitis likes internally within the abdominal cavity. Abdominal tenderness is also significant.

Other symptoms of an inflamed abdomen include nausea and vomiting, fever,  change in bowel habit, sensation of fullness in the abdomen, reduced urine output, loss of appetite, thirst, fatigue and malaise (a general feeling of being unwell) may also be present to varying degrees.

Treatment of Inflamed Abdomen

The treatment of peritonitis depends on the underlying cause. While peritonitis may at times be treated on its own, it is also important to treat the causative condition to prevent a recurrence. Antibiotics are used for bacterial peritonitis and this may be administered either orally or intravenously, depending on the severity of the infection. It is also administered to prevent any further spread of the infection to intra-peritoneal organs in particular.

Abscesses need to be drained. This may not always require surgery. Non-surgical drainage can be done percutaneously. However, in more severe cases surgery may be necessary to isolate the source of the infection can remove infectious material. This can be done in a single surgical procedure or may require two or three procedures to adequately manage the infection.

Dietary modification may be necessary during treatment especially when complications like sepsis arise. This should be prescribed by a dietitian in conjunction with the supervising doctor.


Since people undergoing peritoneal dialysis are at high risk of an infection, certain preventative measures should be adhered to. This includes proper washing of the hands with an antiseptic soap before touching the catheter and using a surgical mask while undergoing dialysis. Other causes of peritonitis may not be as simple to avoid due to the nature of the underlying conditions that cause it.


With prompt treatment, peritonitis can be effectively treated and complications may be prevented. However, patients with underlying conditions like cirrhosis may be at risk of recurrent peritonitis. The long term prognosis in these cases is poor. Even without underlying conditions like cirrhosis, the prognosis is also poor in very severe infections with mortality rates as high as 30% to 50% of cases.



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