• Appendicitis means inflammation of the appendix, which is a small tube attached to the large intestine.
  • Appendicitis is a medical emergency.
  • Treatment may include intravenous antibiotics or surgical removal of the appendix.
The appendix is a thin tail, tube or appendage growing out of the caecum, which is part of the large intestine located on the lower right side of the abdomen. The precise function of the appendix in the human body is something of a mystery, although it clearly plays a role in digestion for other animal species.

Appendicitis means inflammation of the appendix. Food or faecal matter can sometimes lodge in the narrow tube of the appendix, and the blockage becomes infected with bacteria. This is a medical emergency. If the appendix bursts, its infected contents will spread throughout the abdominal cavity. Infection of the lining of the abdominal cavity (peritonitis) can be life threatening without prompt treatment.

Anyone of any age can be struck by appendicitis, but it seems to be more common during childhood and adolescence. It is less common for anyone over the age of 30 years to develop appendicitis. Treatment options include surgery.

Symptoms of appendicitis

Symptoms of appendicitis include:
  • dull pain centred around the navel, which progresses to a sharp pain in the lower right side of the abdomen
  • pain in the lower back, hamstring or rectum (less commonly)
  • fever
  • vomiting
  • diarrhoea or constipation
  • loss of appetite.

Causes of appendicitis

The cause of acute appendicitis is still unclear. A number of studies have indicated that obstruction of the appendix usually occurs during appendicitis, while others dispute that obstruction is the cause of appendicitis. Often, a small amount of faecal matter (poo) is present in the appendix at the time of the appendicectomy. There is no direct evidence that diet plays a role in causing appendicitis.

Many people treated for acute appendicitis may have had previous episodes of appendicitis that they did not seek treatment for.

Perforated appendix

If pus builds up in the appendix, it will eventually burst, flooding the abdominal cavity with infected matter. Bursting, or perforation, can occur 36 hours or so from the onset of infection. The signs of a perforated appendix include a severe worsening of symptoms and collapse.

Infection of the lining of the abdominal cavity (peritonitis) is a life-threatening complication and requires immediate emergency treatment.

Diagnosis of appendicitis

Appendicitis can mimic the symptoms of other disorders such as gastroenteritis, ectopic pregnancy and various infections (including those of the kidney and chest).

Diagnosis may include a thorough physical examination and careful consideration of the symptoms. If the diagnosis is not clear, then laboratory tests and ultrasound or CT scans may be needed.

Since appendicitis is potentially life threatening if left untreated, doctors will err on the side of caution and operate, even if there is no firm diagnosis.

Treatment for appendicitis

Treatment includes an operation to remove the appendix completely. This procedure is known as an appendicectomy or appendectomy. The appendix can often be removed using laparoscopic (keyhole) surgery. The surgeon will use a slender instrument (laparoscope), which is inserted through tiny incisions (cuts) in the abdomen. This eliminates the need for an abdominal incision.

If this is not possible, a small incision is made in the lower abdomen. The appendix is cut away and the wound on the large intestine stitched. If the appendix has burst, the surgeon will insert a tube and drain the abdominal cavity of pus. Antibiotics are given to the patient intravenously to reduce the possibility of peritonitis.

The typical hospital stay for an appendicectomy is between three and five days. Removing the appendix appears to have no effect on the workings of the digestive system, in either the short or long term.

An alternative to surgery is antibiotic therapy. Studies that have compared the outcome of surgery to the outcome of antibiotics show that about 70 per cent of cases may resolve with antibiotic therapy and not require surgery. However, the factors leading to failure of antibiotic therapy are not known, so antibiotic therapy alone is usually reserved for patients too frail to undergo surgery.

Where to get help

  • Your doctor
  • NURSE-ON-CALL Tel. 1300 60 60 24 – for expert health information and advice (24 hours, 7 days)
  • If you suspect appendicitis, call 000 for an ambulance or go to your nearest hospital emergency department immediately.

Things to remember

  • Appendicitis means inflammation of the appendix, which is a small tube attached to the large intestine.
  • Appendicitis is a medical emergency.
  • Treatment may include intravenous antibiotics or surgical removal of the appendix.
  • Carr, NJ, 2000, ‘The pathology of acute appendicitis’, in Annual of Diagnostic Pathology, vol. 4, no. 1, pp. 46-58. More information here.
  • Søreide, K, 2007, ‘Should antibiotic treatment replace appendectomy for acute appendicitis?’ in Nature clinical practice. Gastroenterology & hepatology. vol. 4, no. 11, pp. 584-585. More information here.
  • Appendicitis 2000, The Children's Hospital, Westmead, NSW, Australia. More information here.

More information

Digestive system

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Small intestine

Large intestine

Liver and gallbladder

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This page has been produced in consultation with and approved by: Canberra Hospital - Gastroenterology Unit

Last updated: August 2014

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