Appendicitis means inflammation of the appendix. The appendix is a small pouch that comes off the gut wall at the start of the large intestine. Appendicitis is common. Typical symptoms include tummy (abdominal) pain and being sick (vomiting). These symptoms gradually get worse over 6-24 hours. Some people have less typical symptoms. The usual treatment is an operation to remove the inflamed appendix, and the aim is to do this before it bursts (perforates). A perforated appendix is a very serious condition.
What and where is the appendix?
The appendix is a small dead-end pouch, like a little tube, that comes off the caecum. The caecum is the first part of the large bowel (large intestine) just before the colon. The small intestine digests and takes in (absorbs) food. The parts of the food that are not digested begin to be formed into stools (faeces) in the caecum before passing through the large intestine.
The appendix is normally about 5-10 cm long and quite narrow. It has no known function in modern man. However, it is believed our evolutionary ancestors used the appendix to digest tough food, and it is no longer used for this. The appendix does contain some immune tissue, and it has been suggested that the appendix may play some part in defending the body against attack via the bowel, particularly in developing babies. Even so, whatever function it does have, it can be removed without any ill effects.
What is appendicitis?
Appendicitis means inflammation of the appendix. The inflamed appendix becomes infected with germs (bacteria) from the intestine. The inflamed appendix gradually swells and fills with pus. Eventually, if not treated, the swollen appendix might burst (perforate). This is very serious, as the contents of the intestine then leak into the tummy (abdominal) cavity. This can cause a serious infection of the membrane that lines the abdomen (peritonitis), or a collection of pus (an abscess) in the abdomen. So, if appendicitis is suspected, early treatment is best before it bursts.
Who gets appendicitis?
Appendicitis is common and can affect anyone of any age. Teenagers and young adults are the most commonly affected. About 6 in 100 people in the UK have appendicitis at some time in their lives. Appendicitis is the cause of the most common tummy (abdominal) surgical emergency admission to hospital in the UK. It is slightly more common in men than in women. It is much more common in western countries. This is thought to be partly due to the western diet which is often low in fibre.
What causes appendicitis?
The reason why the appendix becomes inflamed in the first place is not known in most cases. Some cases are thought to be due to a blockage that occurs somewhere along the short appendix. This may be due to some hard stools (faeces) that get stuck. It may also sometimes be due to bits of indigestible food being delivered from the small intestine to the large intestine. These should be forced out again by the muscles in the wall of appendix, but if they get stuck then blockage results. Either way, germs (bacteria) may then thrive and cause inflammation behind the blockage in the dead end of the appendix.
What are the symptoms of appendicitis?
Pain in the tummy (abdomen) is usually the main symptom. Commonly, the pain starts in the middle of the abdomen. The pain usually develops quickly, over an hour or so. Over the next few hours the pain typically travels to the lower right-hand side of the abdomen. This is over where the appendix normally lies.
Typically the pain becomes worse and worse over 6-24 hours. The pain may become severe. The pain tends to be more sharp if you cough or make any jarring movements. The pain may ease a bit if you pull your knees up towards your chest. The lower abdomen is usually tender, particularly in the lower right-hand side. You may find that pushing in on this area of your tummy gently with two fingers is very painful. Letting go - releasing the two fingers quickly after you push in - can be even more painful.
Other symptoms that may occur include the following.
- Feeling sick (nausea) and being off food is typical. You may be sick (vomit).
- High temperature (fever) and generally feeling unwell.
- Constipation may occur, and sometimes diarrhoea.
- Frequent passing of urine may develop. This is thought to be due to the inflammation irritating the nearby ureter. The ureter is the tube between the kidney and bladder.
If the appendix bursts (perforates) then severe pain can spread to all the abdomen. Any movement is painful and you won't want to move around at all. You become very ill as you develop serious infection of the membrane that lines the whole abdomen. Coughing and moving the legs at the hips are painful. Your tummy will feel hard and tense, and you won't be able to push into it at all. This is called peritonitis.
In some cases of appendicitis, the symptoms are not so typical. For example, in some cases the pain may develop more slowly and run a more smouldering course. The pain may also start in the lower right-hand side of the abdomen. In some cases the pain may be relatively mild, and may not actually become severe until the appendix perforates. The site of the pain may also not be typical if the appendix lies in an unusual place. Sometimes it is felt around the back passage, for example, or lower down in the groin. In pregnancy the appendix is moved upwards by the presence of the growing baby. The pain can, therefore, begin quite vaguely further up the tummy or even under the ribs.
How is appendicitis diagnosed?
A doctor may diagnose appendicitis quite easily if you have the typical symptoms. However, as described above, not everyone has typical symptoms. Sometimes it is difficult for doctors to be sure that appendicitis is the cause of the symptoms.
Some people develop pain that is similar to appendicitis, but which is caused by other conditions. For example:
- Pelvic inflammatory disease.
- Cystitis (urinary tract infection).
- Passing a kidney stone (ureteric colic)
- Inflammation of the large bowel (large intestine) - a condition called colitis.
- Inflammation of the the first part of the large bowel (the caecum) itself - sometimes seen in Crohn's disease.
- In women the right ovary lies near to the appendix, so pain in this area could come from either organ.
- In children swollen glands in the tummy around the bowel (mesenteric adenitis), often associated with viral infections can mimic appendicitis.
- Occasionally pain from gallstones or from inflammation of the gall bladder (cholecystitis) can mimic appendicitis
Some people have surgery only to find that the appendix is normal and not inflamed.
There is no easy and foolproof test to confirm appendicitis. A surgeon often has to make a judgement whether to operate or not. It depends on whether the symptoms and also the findings when you are examined suggest that appendicitis is the probable diagnosis. Your doctor will examine your tummy (abdomen) to assess where you are tender.
Blood tests are also done when you are admitted to hospital, and this may also help diagnosis. Urine testing is done to rule out urine infection, and women are usually offered pregnancy tests. Trials of a urine test looking for a protein called LRG are also continuing, which may help in diagnosis. Levels of LRG are very raised in the urine in appendicitis. However, this test is not yet widely available.
Imaging tests are often used to help decide on the diagnosis, if it is not clear. For example, an ultrasound scan or a CT scan may help to clarify the cause of the symptoms. If the diagnosis seems obvious or there is concern that your appendix has, or is about to, burst (perforate), you are likely to go straight to surgery. This will avoid the delay caused by taking you for a scan first.
Sometimes a surgeon advises to wait and see for a few hours or so while you are being monitored in hospital. This allows some time to see if your symptoms progress to a more definite diagnosis, or even if they change or go away. Antibiotic medicine will usually be given in this time.
What is the treatment for appendicitis?
You will be admitted to hospital if appendicitis is suspected. An operation to remove the inflamed appendix is usually done quite quickly once the diagnosis is made. It is much better to remove an inflamed appendix before it bursts (perforates). The inflamed appendix is found and cut off at the first part of the large bowel (large intestine) - the caecum. The hole left in the caecum is stitched up to stop any contents from the gut leaking out. Antibiotic medicine is given before the operation to reduce the risk of an infection developing at the site of the operation.
Antibiotics play an important role in the management of appendicitis. Sometimes antibiotics are used to delay surgery until the appendicitis has calmed a little. This may make the surgery safer and reduces the risk that the appendix will burst at operation.
Studies have suggested that in some cases appendicitis can be treated with antibiotics alone, without the need for surgery. This removes the risks associated with surgery, but does mean that the appendicitis could return (relapse) later. This area remains controversial and as yet it is not established or routine practice.
Removal of the appendix is one of the most commonly performed operations in the UK. In most cases, the operation is done before the appendix perforates. This is usually a straightforward and successful operation needing just a short recovery. However, surgery can be more difficult and you will take longer to recover if the appendix has perforated.
Surgery is commonly done by a keyhole operation, as the recovery is quicker compared to having an open operation. The keyhole operation is performed through three tiny cuts, the largest of which is only around 1.5 cm in size.
Sometimes keyhole surgery isn't recommended and open surgery is performed instead. This is likely to be needed if the appendix has already burst and formed a lump called an appendix mass. It is also more likely if:
- You have had other tummy (abdominal) surgery and have scarring.
- During the keyhole surgery a blood vessel is damaged by the instruments and needs repair.
There are usually no long-term complications after the operation. As with any operation, there is a small risk of complications from the operation itself and from the anaesthetic. However, if you don't have an operation, an inflamed appendix is likely to perforate and cause a serious infection in the abdomen (peritonitis). This can be life-threatening, and indeed an untreated burst appendix with peritonitis has caused many deaths in history. The famous magician, Harry Houdini, used to invite members of the audience to punch him in the stomach to demonstrate his strong abdominal muscles. Unfortunately, someone did this when he was unprepared. Even more unhappily, he had appendicitis at the time. His appendix burst, and this resulted in his death some hours later.
Further reading & references
- Humes DJ, Simpson J; Acute appendicitis. BMJ. 2006 Sep 9;333(7567):530-4.
- Craig S, Appendicitis, Medscape, Jul 2011
- Kentsis A, Lin YY, Kurek K, et al; Discovery and Validation of Urine Markers of Acute Pediatric Appendicitis Using High-Accuracy Mass Spectrometry. Ann Emerg Med. 2009 Jun 25.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Tim Kenny
Dr Mary Lowth
Dr Adrian Bonsall