Diverticular disease

Discuss diverticular disease?

  • Diverticulosis of the colon is an acquired condition that results from herniation of the mucosa through defects in the muscle layer at the site where arteries (the vasa recta) penetrate the muscle layer to reach the mucosa and submucosa.
  • Diverticula generally are multiple.
  • The most common site is the sigmoid colon although diverticula can occur throughout the large bowel.
  • Approximately 60 percent of humans over age 60 living in westernized countries will develop colonic diverticula.  It occurs almost exclusively in developed countries.
  • Of patients with diverticula, 80 to 85 percent are believed to remain asymptomatic. The rest may develop a complication: diverticulitis, bleeding, or perforation.

Discuss the aetiology of diverticular disease?
Colonic diverticulae are acquired pulsion diverticulae. The combination of increased intraluminal pressure and weakness in the muscle coat of the colon results in the mucosa bulging through the muscle. Manometric studies show that segmental colon wall contractions, and thus intraluminal pressure, is greatest in the sigmoid.  The mucosa bulges through the weakness in the muscle wall at the site of perforating vessels, between the taenia coli. There is a strong correlation between low fibre diet, low stool bulk, subsequent increased intraluminal pressure and the development of diverticulosis

What is diverticulosis?
Diverticulosis is an anatomic diagnosis that describes the presence of one or more diverticula.  A high fiber diet is recommended to prevent symptomatic diverticular disease, although there are no randomized controlled trials to support or refute this strategy.

Discuss symptomatic diverticular disease?

  • This is characterized by nonspecific attacks of abdominal pain (colicky or steady pain), often relieved by passing flatus or having a bowel movement. Attacks are often precipitated by eating.
  • Bloating and changes in bowel habits also can occur, and constipation is more common than diarrhea.
  • Fullness or tenderness in the left lower quadrant often is appreciated on physical examination.
  • A high fiber diet is recommended
  • These nonspecific symptoms overlap considerably with those of IBS.

The differentiation between symptomatic DD and IBS becomes more important in a patient with significant symptoms in whom surgical treatment is being contemplated. Colon resection will be successful in patients whose symptoms are due to DD, but not in those with DD but symptoms due to IBS. Crucial in this differentiation is evidence of inflammation or diverticulitis.

What is diverticulitis?
Diverticulitis is defined as inflammation and infection related to diverticula. The pathogenesis of diverticulitis is thought to be due to micro or macro perforation of a diverticulum caused by increased intraluminal pressure or erosion by a thickened faecal material in the neck of a diverticulum. Micro perforation leads to a contained infection whereas a macro perforation can lead to an abscess, fistula or peritonitis.

Discuss the clinical features of diverticultis?

Acute constant abdominal pain, most often in left lower quadrant often associated with fever, nausea, vomiting, constipation or diarrhoea.  Dysuria and urinary frequency (sympathetic cystitis) can also occur. Physical examination reveals tenderness with or without local peritoneal signs in the left lower quadrant.

Discuss the diagnosis of diverticulitis?

  • Leukocytosis
  • CT is the test of choice to confirm a suspected diagnosis of diverticulitis. The finding of pericolic fat infiltration is diagnostic.
  • Colonoscopy or barium enema is contraindicated during the acute phase because there is a theoretical possibility to exacerbate perforation.
  • Colonoscopy should be performed six to eight weeks after recovery from acute diverticulitis to exclude coexisting neoplastic disease and confirm the diagnosis of diverticulosis.

Discuss the classification of diverticulitis?

The European Association for Endoscopic Surgeons has developed a classification scheme based upon the severity of its clinical presentation.
Grade I- Symptomatic uncomplicated diverticulitis (Fever, crampy abdominal pain, CT evidence of diverticulitis)
Grade II- recurrent symptomatic uncomplicated diverticulitis
Grade III- Complicated diverticulitis (Haemorrhage, Abscess, Phlegmon, Perforation, Purulent and faecal peritonitis, Stricture, Fistula, Obstruction)

Discuss the treatment of diverticulitis?

  • Outpatient or inpatient depending on the general condition of the patient
  • Broad spectrum antibiotics to cover gram negative rods and anaerobes like fluoroquinolones plus metronidazole or amoxicillin-clavulanic acid.
  • NPO if the patient is unwell
  • Nasogastric suction is not indicated unless there is significant ileus.
  • Pain relief- avoid morphine as it increases intraluminal pressure. Pethidine is preferred as it reduces intraluminal pressure
  • Surgery- 15-30% requires surgery because of the failure of medical management or development of complications like perforation.  In almost all cases this involves a Hartman’s procedure with resection of the involved segment, oversewing of the rectal stump and formation of end colostomy. The Hartmann’s resection has proven to be a safe and effective approach, and is based upon the idea that an anastomosis in the setting of acute infection/inflammation is dangerous and associated with a high rate of suture line breakdown. The resection must remove all thickened diseased colon, but not necessarily all of the proximal diverticulum-bearing colon.  In almost all cases, all of the sigmoid colon should be removed.

Discuss the role of preventive surgery?
Some guidelines suggest pre-emptive surgery for any patient who has had two attacks of acute diverticulitis, with the intention of preventing another attack that could present with perforation and would necessitate a stoma. However recent data suggest that the patients with uncomplicated diverticulitis can be managed nonoperatively regardless of the number of recurrent episodes.
Elective surgery however may be offered to patients who have had two or more episodes of severe diverticulitis, as determined by their clinical presentation and CT grade.

Elucidate the complications of diverticulitis?
Complications of diverticulitis include abscess, fistula, bowel obstruction, and free perforation. These complications all require surgical consultation.
Abscess formation should be suspected when fever, leukocytosis, or both persist despite an adequate trial of appropriate antibiotics.  Abscesses not improving on antibiotics or bigger than 5 cms need CT guided drainage.

Discuss diverticular fistulas?
Peridiverticular abscesses can progress to form fistulas between the colon and surrounding structures in up to 10 percent of patients. Colovesical fistulas account for two thirds of the cases, followed by colovaginal, colocutaneous, and enterocolic cases.  Some fistulas will close spontaneously as the inflammatory process resolves. Therefore, a selective approach should be used, in which operation is offered to those patients with persistent symptoms after 5–6 months after an acute attack. The most commonly reported symptoms in this group of patients include abdominal pain, pneumaturia, cystitis, fecaluria, diarrhea, and hematuria.  Most of these cases should be amenable to resection with primary anastomosis.

Discuss diverticular haemorrhage?

It is the most common cause of major lower GI bleeding and is abrupt, voluminous and painless in onset. It is arterial in nature and is attributed to medial thinning of the vasa recta as they cross over the dome of a diverticulum.  Labelled red cell scan or mesenteric angiography may localise the bleeding point, depending on the local availability and expertise. Advantages of colonoscopy include the potential to precisely localize the site of bleeding and permit therapeutic intervention. Disadvantages include poor visualization in an unprepared colon, and the risks of sedation in an acutely bleeding patient. Surgery is required in patients with ongoing bleeding and haemodynamic instability despite resuscitation, or who require blood transfusion of greater than 8–10 units.

Discuss diverticular colitis?

Some patients with diverticular disease develop a segmental colitis affecting the sigmoid colon. Endoscopic examination reveals a localized sigmoid inflammatory process with normal rectal and proximal colonic mucosa.The inflammatory changes may be mild to florid resembling IBD both endoscopically and histologically. It frequently presents with bloody stools. In some abdominal pain, cramping discomfort or diarrhea may occur. The inflammation is self limited and settles within a few weeks or months without recurrence. Optimal treatment is not known. A high fiber diet, antibiotics (ciprofloxacin plus metronidazole for 7-14 days) and/or aminosalicylates were noted to be helpful in case


  1. Salzman H et al. Diverticular Disease: Diagnosis and Treatment. Am Fam Physician. 2005 Oct 1; 72(7):1229-34.

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