I diverticula are protrusions of the mucosa and submucosa comparable to small pockets, which can form in the digestive tract, but their most frequent site is on the intestinal walls at the level of colon.
What are the differences between diverticulosis, diverticular disease and diverticulitis? We talk about it with the professor Alessandro ArmuzziHead ofChronic Inflammatory Intestinal Diseases Unit in Humanity.
How does the intestine work?
The intestine represents the last part of the digestive system and is responsible forassimilation of nutrients introduced with food andexpulsion of undigested fibers, fats and their derivatives, mucus, intestinal mucosal cells, inorganic and organic substances, bacteria and water in the form of feces.
To carry out its functions, the intestine uses a system of regulation and control of involuntary mechanisms independent of the central nervous system, consisting of over five hundred million neurons, and called enteric nervous system: for this reason it has been renamed “second brain”.
The more than one thousand billion bacteria, divided into more than five hundred different species, which live in the intestine also contribute to the digestive process, constituting the so-called intestinal microbiota.
From an anatomical point of view, the intestine is a tubular organ long on average seven meters and with a total surface, if completely extended, of about 300 square meters. It differs in:
- Small intestine (“Small” intestine), an average of six meters long, and responsible for concluding the digestive process initiated in the mouth and stomach, ensuring the absorption of nutrients taken through food. In turn it is divided into:
- Duodenum: it is the part closest to the stomach, separated from it by the pylorus, and has a characteristic “C” shape with an elongated lower section and is on average 25-30 centimeters long. It regulates the stomach emptying speed and, thanks to the action of pancreatic enzymes, intestinal enzymes and hepatic bile, prepares nutrients for absorption;
- Fast: with an average length of about 2.5 meters, it is the part specialized in the absorption of nutrients, thanks to the intestinal villi that cover it internally. These are folds towards the outside of the intestinal mucosa that allow to enormously increase (by about 600 times) the surface responsible for absorption;
- Ileus: with an average length ranging from 2 to 4 meters, it is the final part, in which the bile acids and vitamin B12 are reabsorbed and the substances not previously metabolized are processed. The residues of this process are then pushed into the large intestine via the ileocecal valve.
- The large intestine (“Big” intestine), less than two meters long on average, it is responsible for the absorption of water and electrolytes. In turn it is divided into:
- Blind: ampoule-shaped and located in the right inguinal region under the ascending colon, it provides for the passage and absorption of water and electrolytes and offers an ideal environment for the proliferation of bacteria involved in the digestion process;
- Colon: it hosts bacteria that synthesize vitamins essential for our body, such as those of groups B and K. Here, also, the non-digestible waste elements accumulate, which will then be pushed into the rectum through peristalsis. The colon is, in turn, divided into four sections:
- Ascending colon: about 15-20 cm long, above the cecum, in the right portion of the abdomen.
- Transverse colon: about 50 cm long, not far from the pancreas and spleen, in the upper part of the abdomen.
- Descending colon: about 25 cm long, it is the continuation of the transverse colon.
- Colon sigmoideo: it has variable length, width and conformation and is so named because it has a characteristic “S” shape, a letter which, in Greek, is called “sigma”. In men it is close to the vas deferens, which is the channel for the spermatic passage, while in women it is located near the left ovary and uterus.
- Rectum: terminal portion of the large intestine, which continues with the sigmoid colon and ends with the anus, which is the site of temporary storage of waste materials which will then be expelled, through the opening of the anal canal, in the form of feces.
Diverticulosis, diverticular disease and diverticulitis: what are the differences?
As already mentioned, diverticula are protrusions of the mucosa and submucosa (therefore, they are actually pseudo-diverticula) comparable to small protruding pockets that can form in various points of the digestive tract, but which more often develop at the level of the intestinal wall of the colon.
In particular, the colon wall is made up of four layers, which starting from the inside are mucosa, submucosa, muscular tunic and serous tunic. The process of diverticula formation occurs when the two innermost layers of the wall, i.e. mucosa and submucosa, make their way, adjacent to the entry points of the small blood vessels that supply the wall itself, until they protrude into the abdominal cavity.
Generally a distinction is made between:
- diverticulosis: present in less than 10% of individuals under the age of 40, and in over 50% of individuals over the age of 60, it is characterized by the asymptomatic presence of diverticula; in fact, in 80% of cases, these are discovered by chance during a colonoscopy, ultrasound or other abdominal radiological examination performed for other reasons. In Western populations they are mainly located in the left colon (> 95% in the sigma), while in Asian populations they are more frequent in the right colon;
- uncomplicated symptomatic diverticular disease: up to 15% of people with diverticulosis may report symptoms such as swelling, abdominal pain (especially in the lower left of the abdomen) and alteration of intestinal regularity, which can be superimposed on those of the irritable colon;
- diverticular disease with acute diverticulitis: Up to 5-10% of people with diverticulosis may develop infection / inflammation of the diverticula which involves symptoms such as severe and prolonged abdominal pain, associated with constipation / diarrhea, bloating, nausea, decreased appetite, and accompanied by fever. It can be further divided into uncomplicated diverticulitis (localized infection / inflammation) and complicated (associated with abscess, peritonitis or bleeding);
- segmental colitis associated with diverticulosis: a small percentage of subjects with diverticulosis may develop an inflammatory process localized in the colonic mucosa between the diverticula, with endoscopic and histological characteristics similar to those of chronic inflammatory bowel diseases.
What are the causes of diverticula?
The diverticula of the colon represent a rather widespread anatomical alterationwhose training can be supported by:
- genetic predispositionas recently emerged in twin concordance and association studies that have identified some gene variants associated with diverticular disease;
- ageespecially after the age of 40, because as the connective tissue that supports the intestine gets older, it becomes more lax;
- bad eating habits (for example, low-fiber diet);
- taking anti-inflammatories (such as steroid and non-steroidal anti-inflammatory drugs);
- chronic constipationwhich causes greater internal pressure on the colon walls.
Diverticula: what tests to do for diagnosis?
The presence of diverticula can be diagnosed through the following tests:
- virtual colonoscopy which is nothing more than an abdominal CT scan with three-dimensional reconstruction of the colon; this allows accurate observation of the internal intestinal wall in a non-invasive way, without inserting an endoscopic probe into the intestine;
What to do in case of diverticulosis or uncomplicated diverticular disease?
In the presence of diverticula, even in the absence of symptoms, it is generally recommended to undergo one annual gastroenterological check-up.
Following the diagnosis of diverticulosis or uncomplicated symptomatic diverticular diseasethe patient is not usually required to adhere to a particular diet, although it is generally recommended to increase the intake of water, cereals, fruit and vegetables, and possibly also to use substances forming soft fecal mass (for example psyllium or macrogol), so as to increase the intake of fiber (at least 30 grams per day) and therefore reduce the internal pressure of the colon (for this reason drugs are also useful antispasmodics), promote intestinal motility and counteract constipation. Periodic treatments based on antibiotic or anti-inflammatory therapy with intestinal action, or based on probiotics can be of some usefulness in reducing intestinal symptoms, but not the frequency of diverticulitis.
How is diverticulitis treated?
In case, instead, of diverticulitis acute the recovery hospital: in most cases, however, the problem is resolved without resorting to surgery (reserved for cases that develop complications or repeated attacks of acute diverticulitis). The gastroenterologist usually proposes one first diet that rests the intestines, avoiding for a few days to take on vegetable fibers, preferring a more liquid diet or in any case that combines carbohydrates and proteins with the right hydration. The diet is then generally combined with one antibiotic therapy.
Can diverticula be prevented?
And proper lifestyle can help reduce the risk of diverticula formation.
In particular, it is advisable to favor one high-fiber, low-fat diet saturated, to counteract any constipation, and to guarantee your body a right amount of water (during meals or immediately after), to promote intestinal peristalsis, that is, the movements that induce the expulsion of feces.
Finally, it is useful to carry out regularly physical activitycommensurate with your health conditions, because the muscular layer of the colon also benefits from it.
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