Diverticular disease of the colon

What it is

Diverticular disorders of the colon include diverticulosis, diverticular bleeding and diverticulitis, three separate problems from the same wall.

• Diverticulosis is an asymptomatic herniation, a diverticulum, of the intestinal wall.
• Diverticulitis is an inflammatory response following micro-perforation of a diverticulum, and is characterized by LLQ abdominal pain and fever.
• Diverticular bleeding follows the rupture of an artery that has penetrated a diverticulum. It is typically painless and usually stops without therapy.

Diverticula themselves are saclike herniations of colonic mucosa that occur at weak points in the bowel wall. They may bleed, which is diverticulosis, or become filled with fecal matter and lead to inflammation, which is diverticulitis; diverticulitis is an acute inflammatory disease caused by bacterial proliferation within existing colonic diverticula.

Causes and risk

Right-sided diverticulosis is more common in Asian populations and tends to present in younger patients, often mimicking appendicitis. A high-fiber diet is recommended to reduce the recurrence of diverticulitis.

How it presents

Diverticulitis gives LLQ abdominal pain with fever. Nausea, vomiting and constipation may go with it, the patient is tender in the left iliac fossa with a positive rebound, and there is a neutrophilic leukocytosis with a raised CRP. The chronic picture without inflammation is different: chronic constipation with left sided lower pain, usually worse with meals and better with a bowel habit, close to IBS. Steady weight makes colorectal cancer less likely, and chronic IBD usually gives bloody diarrhea rather than constipation. Dysuria, urinary frequency and urgency may reflect bladder irritation. Pneumaturia, fecaluria, or recurrent and polymicrobial UTI suggest a colovesical fistula. Diverticulosis is most commonly associated with substantial painless rectal bleeding, but not with significant abdominal pain. And the presentation of diverticulitis may be indistinguishable from acute appendicitis, which happens when the patient has a redundant sigmoid lying on the right side of the abdomen, or when a cecal diverticulum becomes inflamed.