Diverticular disease/diverticulitis (synonyms: Protrusions of the intestinal wall; colonic diverticulosis; intestinal diverticulitis; intestinal diverticulosis; diverticulitis; diverticular disease; diverticulosis; colonic diverticulosis; ICD-10-GM K57.-: Diverticulosis of the intestine) is inflammation of the wall of the diverticulum. If the area surrounding the diverticulum is also involved in the inflammation, it is referred to as peridiverticulitis. A diverticulum is an outpouching of wall parts of a hollow organ, which can be fungus-, pear- or sac-shaped. Diverticula are either congenital or acquired and occur particularly in the digestive tract and there predominantly in the left-sided colon (large intestine), especially in the sigmoid colon (sigmoid colon). Colonic diverticula are acquired protrusions of the mucosa (mucous membrane) and submucosa (connective tissue layer below the mucosa) through muscle-weakened gaps in the colon wall. “Diverticular disease” of the colon is present when diverticulosis leads to symptoms and/or complications. Acute diverticulitis results in an inflammatory process that originates in the colonic diverticula (peridiverticulitis), spreads to the intestinal wall (focal pericolitis), and can result in severe complications (abscess and/or fistula formation, covered perforation, open perforation with peritonitis, stenosis, diverticulitic tumor). Other possible complications of diverticular disease include colonic diverticular hemorrhage. Chronic diverticulitis is characterized by recurrent (recurrent) or persistent (persistent) episodes of inflammation that can lead to complications (stenosis, fistulas). Symptomatic uncomplicated diverticular disease is defined as persistent or recurrent symptoms attributable to diverticulosis – without the presence of apparent (“appearing”) diverticulitis. In 95% of cases, sigmoid diverticulitis is present; also called “left-sided appendicitis.” In one percent, diverticulitis may occur in the transverse colon (transverse colon) and in two percent each in the ascending colon (ascending colon) and caecum (appendix; the most anterior section of the colon; often then misdiagnosed as appendicitis/appendicitis). If all layers of the wall, including the muscular layer, are involved in the protrusion, this is called a true diverticulum. In contrast, in a pseudodiverticulum (Graser’s diverticulum), only the mucosa bulges through the muscular gaps in the intestinal wall. Diverticulosis (diverticular disease) is said to occur when multiple inflammation-free diverticula are present. Peak incidence: The maximum incidence of diverticulosis is over 70 years of age. Diverticular formation is rare in those under 40 years of age. The average age of hospitalized patients treated for diverticular disease is approximately 62 years. The prevalence (disease incidence) ranges from 28-45% in the general population – approximately 13% for those under 50 years of age, approximately 30% for those between 50 and 70 years of age, approximately 50% for those between 70 and 85 years of age, and approximately 66% for those older than 85 years of age in Western countries. Diverticulitis then occurs at some point in 10-20% of these people. The prevalence of diverticulosis is low in Africa and Asia (approximately 10%). Course and prognosis: Diverticulitis is usually accompanied by fever and colicky pain in the lower abdomen. In the course of diverticulitis, bacteria can accumulate in the diverticula and abscesses (encapsulated pus foci) can form. A feared complication of diverticulitis is covered or open perforation (rupture) of intestinal diverticula, whereby the bacterial content of the inflamed diverticulum is released into the abdominal cavity. This can lead to life-threatening infectious peritonitis (inflammation of the peritoneum). Furthermore, recurrent (recurring) painful episodes, stenosis (narrowing of the intestine), fistulas and lower gastrointestinal bleeding (UGIB; bleeding from the gastrointestinal tract) may occur in the medium to long term. Another possible complication is ileus (intestinal obstruction). The recurrence rate is 2-35%; it depends on the severity of acute diverticulitis.The lethality (mortality related to the total number of people suffering from the disease) is less than one percent for phlegmonous (“spreading diffusely”) diverticulitis, one to three percent for abscessing (“formation of abscesses/pus foci”) diverticulitis, and 12 to 24 percent for free perforation (i.e., the hernia site is sealed by an adjacent organ). Patients on immunosuppressive therapy are at particular risk. Comorbidities (concomitant diseases): Diverticulosis is increasingly associated with hypothyroidism (hypothyroidism; 2.4-fold risk) and arterial hypertension (high blood pressure). Diverticulosis may rarely be associated with segmental colitis (inflammation of the bowel with segmental involvement) (SCAD).
