Diverticular disease, Diverticulosis and Diverticulitis- What is the difference?
This disorder is characterised by the development of pockets or ‘diverticula’ within the colon wall. These diverticula tend to develop in the weak areas of the bowel, in particular, sites where a large number of bloods vessels penetrate the walls of the bowel and in areas that are generally narrower than most others- such as the sigmoid colon.
It is believed that the development of diverticula is a result of the adoption of western diets, which tend to be low in fibre.
This is evident in developed or industrialised countries. Due to the large amounts of refining processes implemented within the food system, the amount of fibre contained in many foods is severely diminished. A diet low in fibre results in the production of stools of a different consistency to normal. This consistency requires a higher pressure to be present in order to move the stools through the bowel. It is the presence of these high pressures that result in the bowel expanding or ‘pocketing outwards through the surrounding muscle, consequently forming the pocket like structures known as diverticula.
Diets high in beef and animal products as opposed to plants foods are also shown to result in diverticular disease. This is due to similar reasons as mentioned above. Animal products contain little amounts of fibre, whereas plant products are the main supply for fibre in the diet. Should an individual limit the amount of plant foods they consume, whether intentionally or unintentionally, they limit the amount of fibre in the diet, resulting in an increase in pressure in the bowel and consequent development of diverticula.
Studies have shown that diets high in vegetable foods, such as those in developing countries, decrease the chances of developing diverticular disease, as these foods are high in fibre and thus decrease the amount of pressure required to move stools through the bowel.
It has also been identified that there may be a genetic component affecting the development of diverticular disease. This suggests that raised pressure in the bowel may be hereditary.
Another factor associated with diverticular disease is age. Diverticular disease is commonly found in individuals over the age of forty.
It is estimated that one third of the population at forty years of age and two thirds of the population at eighty years of age have diverticular disease.
Individuals already suffering form colonic mobility problems or from defects in the strength of the colon wall are also at risk of developing diverticular disease. This is due to the presence of sections of the colon that do not work effectively, resulting in isolated segments with high levels of pressure which consequently lead to the development of diverticula within these segments.
Diverticular disease does not affect people based on gender. Studies have shown the male to female ratio of the incidence of diverticular disease to be equal.
Generally, the condition does not discriminate race-wise if the individuals have adopted the same culture and consequent diet (i.e. a western diet), however will affect according to race if different cultural diets have been adopted.
The term diverticula disease is an overall description of the condition, and encompasses the two phases of the disease, diverticulosis and diverticulitis.
Diverticulosis: This term refers to the presence of diverticula (pockets) within the colon. A person with diverticulosis may have no symptoms and it is possible that they may never develop the active phase of the condition.
Diverticulitis: This term describes the active phase of the disease, in which the diverticula become inflamed. Current belief is that diverticulitis occurs when bodily fluids or faecal matter becomes trapped in the diverticula. This creates a perfect environment in which bacteria can manifest and consequently cause infection. The infection may proceed in one of four ways.
1) The infection may spontaneously resolve itself without medical intervention.
2) The infection may progress, leading to more serious complications (mentioned in chapters 2 and 3).
3) The infection may cause partial or complete obstruction of the bowel. This generally must be addressed via surgery.
4) The infection may fistulize. If the infection is not treated the site of infection will spread and consequently break through to another organ or cavity of the body, creating a tunnel or fistula (explained in chapter 3).
Diverticulitis does not occur in every individual with diverticulosis. In reality only a small proportion of those with diverticulosis will develop diverticulitis.
From the above information, it can be concluded that diverticular disease is the encompassing term for diverticulosis (the inactive phase of the disease in which the diverticula exist, but are not infected or inflamed) and diverticulitis (the active phase of the disease in which the diverticula are inflamed and infected due to the presence of bodily fluid or faecal matter trapped inside).
Diverticular disease can be diagnosed via one of three procedures:
1) Colonoscopy: This procedure involves a thin, lighted tube being passed through the rectum in order for a doctors to obtain a thorough look at the bowel wall. This also enables the removal of small pieces of the bowel wall for further investigation via biopsy.
2) Single Contrast Barium Enema: A thin tube is passed through the rectum in order to feed a white liquid known as barium into the bowel. The presence of the barium allows for the outline of the walls of the bowel to show in an x-ray. If over activity due to presence of the disease is prevalent, the bowel wall will appear thickened.
3) Double Contrast Barium Enema: If it is believed that an individual may have diverticular an enema (thin tube passed through the rectum) may be implemented to view the wall of the colon. The double contrast enema is more accurate than a single contrast enema.
An enema is not used if there is any possibility of diverticulitis (inflamed diverticula) as this may increase the risk of perforation of the diverticula.
4) Computerised Tomography (CT) Scan: This procedure is less invasive than the aforementioned as it does not required a tube to be passed through the rectum. Instead a scan is used to produce a 3D image on a computer screen in which the bowel can be viewed. If possible, Ct scans are used where possible due to the high degree of accuracy in diagnosing diverticula disease and identifying the development of abscesses.
5) Water-soluble contrast enema: Another form of enema- this enables imaging of the intraluminal space and consequent diagnosis of diverticular disease.
6) Ultrasonography: This test is equally as accurate and non-invasive as a CT scan in diagnosing acute colonic diverticulitis if the operator of the machinery is well trained and reliable. Ultrasonography involves the use of a skin probe that emits sound waves. Like an ultrasounds, these sound waves produce echoes which form a picture of organs and tissues inside the body on an ultrasound machine.
For those diagnosed with diagnosed with diverticular disease, many will find that their diverticula will cause them no problems and that they never develop the active phase of the disorder (diverticulitis). Some may develop this phase once or very rarely and will recover very quickly form the event via treatment through optimal diet and antibiotics. There are however the rare cases in which the diverticular disease and consequent diverticulitis are more severe. Approximately ten to twenty percent of those with diverticulosis will develop the active phase of the disease (diverticulitis).
Doctors are unsure as to the exact cause of diverticulitis, which can occur suddenly and without warning. As mentioned above current belief is that inflammation occurs when stools or bacteria become caught in the diverticula, which consequently becomes infected.
