Diverticulosis

What are colonic diverticulosis and diverticulitis?

Colonic diverticulosis is a condition in which small sac-like protrusions (approx. 3-10mm in size) form in the wall of the colon in areas where the muscular layer of the intestinal wall is weakened (Figure 1). Weakening of the muscular layer is associated with ageing (as a result, tissue strength and elasticity change), chronic constipation and a low-fibre diet (as a result, the frequency of passage of intestinal contents decreases and pressure in the intestine increases). Diverticula most commonly develop in the descending colon and sigmoid colon, which is related to physiological characteristics – toward the terminal part of the digestive tract, pressure inside the intestine increases, facilitated by intestinal peristalsis (movements). Nevertheless, diverticulosis may also develop in any other part of the colon. The association between the development of diverticulosis and diet is also supported by its prevalence in different populations – e.g., in North American countries, in people after 60 years of age it is found in up to 50%, whereas in Asian countries it is found in only around 1%.

Diverticulitis is acute inflammation of the colonic wall that develops in the area of a diverticulum (Figure 1). This inflammation is most commonly caused by undigested food particles or faecal fragments (in the case of hard stools), which obstruct this sac-like protrusion in the intestinal wall; as a result, inflammation develops and the normal intestinal microflora proliferates, promoting the development of infection in this area. Although diverticulitis most often affects elderly people (more often women), it is nevertheless found in ~20% of cases before 50 years of age (more often in men).

What are the symptoms of diverticulosis and diverticulitis?

Diverticulosis does not cause symptoms unless inflammation (diverticulitis) has developed. Nevertheless, the term “diverticular disease” is described, which is characterised by various gastrointestinal symptoms, e.g., periodic abdominal pain, meteorism (abdominal bloating), changes in bowel movements (constipation or diarrhoea). These symptoms are non-specific and overlap with symptoms of irritable bowel syndrome, and it is often difficult to differentiate them.
In diverticulitis various acute symptoms are characteristic, the severity of which depends on the severity of inflammation. Depending on the course of diverticulitis, it is classified as uncomplicated or complicated diverticulitis.

Acute diverticulitis is a clinically urgent condition, and in this case medical advice or care at a healthcare facility providing emergency care must be sought immediately. By performing an objective assessment and the additionally required investigations, it is possible to evaluate the severity of diverticulitis and decide on the necessary treatment.

How are diverticulosis and diverticulitis diagnosed?

Diverticulosis is most often identified as an incidental finding during colonoscopy or during computed tomography (CT) examination of the abdominal cavity for another reason. If acute diverticulitis is suspected, colonoscopy must not be performed due to the risk of intestinal perforation (rupture). In this case, the diagnosis is confirmed based on the characteristic clinical signs and radiological findings (usually by performing CT).

What may be the consequences after previous diverticulitis?

After an episode of acute diverticulitis, the following may develop (Figure 2):

• Recurrent diverticulitis or repeated episodes of diverticulitis. After uncomplicated diverticulitis, 15-25% of patients experience a repeated episode, whereas after complicated diverticulitis – approximately 25-30% of patients. Most often, the repeated episode occurs during the first year. The severity of the next episode of disease is usually difficult to predict. Each subsequent episode of disease increases the risk of development of the next episode. Risk factors that promote recurrence of diverticulitis: age (younger than 50 years), obesity, smoking, a low-fibre diet, constipation, a sedentary lifestyle. Sometimes a chronic course of disease may also develop, resulting in mild but persistent complaints (pain on the left side of the abdomen associated with eating, bowel movements or physical activities).
• Colonic stenosis or cicatricial narrowing. Most often, as a result of repeated or chronic inflammation, scar tissue forms in the intestinal wall; as a result, the intestinal wall in this area becomes inelastic and narrows. It is most often characterised by chronic bowel movement disturbances, meteorism, and abdominal discomfort.
• Colonic fistula. This is a pathological connection between the colonic wall and the wall of an adjacent organ (urinary bladder, small intestine, less often – skin), which develops as a consequence after previous complicated diverticulitis or as a result of chronic inflammation. In this case, symptoms are characteristic and vary depending on the organs involved in the chronic inflammatory process.

In which cases is surgical treatment necessary?

Surgical treatment is indicated in cases of acute complicated diverticulitis when the existing clinical situation cannot be resolved conservatively. In this case, an open-type operation (laparotomy) with removal of the inflamed intestinal segment (colon resection) is most often performed. Because of the acute process, the operation is often completed by bringing the intestine out onto the anterior abdominal wall, i.e., creation of a stoma.
In cases where recurrent diverticulitis is observed, surgical treatment in an elective setting should be considered. Indications are determined by the patient's current quality of life, intensity of complaints, as well as investigation findings. The aim of elective surgery is to eliminate the chronic inflammatory process and protect against the possible future development of complicated diverticulitis. The operation is most often performed laparoscopically (in a minimally invasive manner), and during it the entire anatomically altered part of the colon (where diverticula are found) is removed. A new colon connection is created, which allows bowel movements to be maintained via the natural route (Figure 3).
If chronic complications associated with previous diverticulitis (stenosis, fistula) have developed, surgical treatment is recommended in all cases, considering that they cannot be resolved with conservative treatment methods.

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