What are Colonic Diverticulosis and Diverticulitis?

What are Colonic Diverticulosis and Diverticulitis?

A diverticulum is an invagination, protrusion, herniation of the mucosa through the muscular layer of the colon (large intestine).

The term Diverticulosis refers to the presence of non-inflammatory and asymptomatic diverticula; in turn, diverticulitis consists of the inflammation of these aforementioned diverticula, which could cause a varied symptomatology secondary to the inflammatory process established in the diverticulum or around it, often compromising neighboring structures (peridiverticulitis).

Next, some concepts will be clarified which are sometimes misunderstood and it is of great importance for all people to know exactly what we are referencing. 

  • Diverticular disease: It is a clinical term used to describe the presence of symptomatic diverticula.
  • Diverticulosis: Refers to the existence of diverticula without inflammation (asymptomatic).
  • Diverticulitis: Refers to the inflammation and infection related to diverticula which occurs in 10 to 25% of people with diverticulosis.
  • False diverticula: Include most colonic diverticula in which the mucosa and muscularis mucosae herniated through the colon wall.
  • True diverticula: Include those that comprise all the layers of the intestine wall, they are rare and almost always of congenital origin.
  • Pulsion diverticula: Include those that result from high intraluminal pressure.
  • Peridiverticulitis: This is when the inflammation spreads to the surrounding tissues and organs.


This disease can be found in about a third of people over 60 years of age, with more prevalence in Western countries and places where the diet is rich in fiber it is rare (rural Africa).

Even though many patients with colonic diverticulosis remain asymptomatic, around 25% will present with an episode of acute diverticulitis (the main inflammatory complication of diverticular disease).

Which are determining factors for the appearance of these diverticula?

  • Changes in diet (increased consumption of refined sugar, meat and fats, with decreased intake of wheat fiber).
  • Constipation.
  • Physical inactivity.
  • Aging (weakening of the colon walls).
  • Genetic patterns (family tendency).
  • Multiple endocrine neoplasia type IIB syndrome.
  • Smoking habit.
  • Long-term treatment with nonsteroidal anti-inflammatory drugs.
  • Constitutional disorders, diverticulosis coexisting with diaphragmatic hiatus hernia, cholelithiasis (Saint's triad).

Signs and symptoms of the disease

  • Abdominal pain (in the lower left quadrant) acute or colicky and gets better with the expulsion of gases.
  • Change of intestinal habit (constipation or diarrhea).
  • Abdominal distension.
  • Nausea and vomiting.
  • Abdominal tenderness.

Complementary exams

There are several studies that could be indicated in patients with this disease, however, the main study in patients with Diverticular disease of the colon is Computerized Axial Tomography (CAT scan).

It is the most appropriate test for the assessment of clinical suspicion of diverticulitis, it has great sensitivity and specificity, it also has the wonderful characteristic that it can identify complications such as abscess, fistula, compromise of other organs, among others.

Chronic diarrhea: occurs due to bacterial overgrowth, generally in cases of extensive jejunoileal diverticulosis 1 , 3 , 6 , 9 ( Figure 8 and Figure 9 ).

Figure 8 CT enterography in coronal section, portal phase, of an 84-year-old patient under study for evacuation rhythm abnormalities with diarrhea of months of evolution: multiple false diverticula (arrows) were identified in jejunal loops, with no signs of complication.

Figure 9. Entero-CT in non-contrast phase, in (a) coronal and (b) axial views, of a 46-year-old patient with a history of kidney-pancreatic transplant under study for chronic diarrhea: a formation with a false diverticular appearance was discovered in continuity with the duodenum, probably favoring a mechanism of bacterial overgrowth as a cause of chronic diarrhea (arrows).


Diverticular disease does not require specific treatment, it is enough to readjust the diet, eliminate the smoking habit, as well as obesity, perform physical activity frequently and prevent the different risk factors. Medical and sometimes surgical treatment is reserved for the different complications that this disease can cause. We will emphasize the treatment of acute diverticulitis (inflammation of the diverticula).

The mere presence of diverticula is not an indication for surgery; however, there is a subgroup of patients that due to different factors require surgical treatment (surgery).

Indications for elective (non-urgent) surgical treatment:

  • Two or more attacks of diverticulitis (inflammation), associated with abdominal pain, fever, abdominal mass, and leukocytosis.
  • Symptoms of urinary obstruction.
  • More than two confirmed episodes of severe acute diverticulitis requiring hospitalization.
  • Immunocompromised patients.
  • A single attack of diverticulitis in people under 50 years of age.

Medical treatment

Uncomplicated acute diverticulitis

Medical Treatment (For individuals in good general condition).

  • Outpatient treatment with broad-spectrum oral antibiotics for 7 or 10 days and a low-residue diet.

Antibiotic recommendation

Outpatient Oral Regimens:

  • Metronidazole and a Quinolone (Ciprofloxacin).
  • Metronidazole and trimethoprim–sulfamethoxazole.
  • Amoxicillin–clavulanate. 

For patients with abdominal pain, leukocytosis, fever. 

  • Inpatient treatment with parenteral antibiotics and intestinal rest (suspension of oral intake and sometimes placement of a nasogastric tube to prevent vomiting and bronchial aspiration). 

Intravenous regimens for inpatients in hospitals or other health care facilities:

  • Metronidazole and a Quinolone.
  • Metronidazole and a 3rd generation cephalosporin (Ceftriaxone).
  • Beta-lactam with a beta-lactamase inhibitor. 

Follow-up care

Your doctor may recommend a colonoscopy six weeks after your recovery from diverticulitis, especially if you haven't had a colonoscopy in the previous year. There does not appear to be a direct link between diverticular disease and colon cancer or rectal cancer. But colonoscopy, which is risky during a bout of diverticulitis, can rule out colon cancer as a cause of your symptoms.

After successful treatment, your doctor may recommend surgery to prevent future episodes of diverticulitis. This decision is taken individually and is generally based on the frequency of attacks and whether complications have occurred.

Surgical Treatment (Surgery)

  • Less than 10% of patients with acute diverticulitis require surgical treatment during their hospital stay.
  • 50 to 70% improve with treatment and have no more episodes.
  • The risk of complications increases with recurrence.
  • Indications for emergency surgical treatment include generalized peritonitis, poorly controlled sepsis, unblocked visceral perforation, the presence of a large abscess inaccessible to drainage, and lack of improvement or deterioration during the first 3 days of medical management; These pictures are characteristic of Hinchey stages 3 and 4.

Laparoscopic surgery (minimally invasive).

  • Many surgeons now advocate laparoscopic resection for patients with stage 1 or 2 of the disease, but this approach is not fully accepted for stages 3 and 4. Laparoscopic Colectomy (colon resection) may become the standard surgical approach for uncomplicated diverticulitis as more surgeons become technically trained.


In summary, in case of cecal or right colonic diverticulitis without complications, it seems that non-surgical treatment is the best approach, even in case of recurrence. In case of complicated diverticulitis, with 2 or more episodes of recurrence, resistant to medical treatment, suspicious of malignancy and in those cases in which a precise differential diagnosis cannot be established (especially in the case of cecal diverticulitis), surgery should be considered. Laparoscopy is the best surgical approach, especially in young patients. More studies are needed, especially in the West, to determine the exact incidence of this disease and to define a precise treatment.