Diverticulitis & Diverticular Disease

Diverticula are small outpouching of the colonic wall at weakened area of the colon. While diverticula can occur in other parts of the intestinal tract, they are most common in colon and most likely to cause symptoms in sigmoid colon. The outpouching were thought to be related to high pressure on the colonic wall, such as straining to pass stool when constipated. The chances of having diverticula increases with age. When diverticula are present but not causing any symptom, the condition is called diverticulosis. Only 20% of people with diverticulosis develop symptoms due to disease process. Diverticular disease does not lead to colon cancer, however the two conditions may have similar symptoms and CT scan findings.

Diverticular disease types and symptoms

Disease processes associated with colonic diverticula include:

  • Diverticulitis – inflammation of diverticula and adjacent colon. Typical symptoms include lower abdominal pain, fever, change in bowel habit (constipation or loose stool). More severe inflammation results when a diverticulum perforates causing feces and bacteria to spill out from the colon into the abdominal cavity. Small "contained perforation" may cause an abscess, but larger "free perforation" can cause peritonitis (a life-threatening infection of abdominal cavity) and often require emergency surgery.

  • Diverticular fistula – when inflamed diverticulum erodes into adjacent organ, forming a small "tunnel" that allows stool and bacteria from the colon to travel to the other organ. Most common fistulas are to the bladder (colovesical fistula) resulting in air and fecal particles in the urine and recurrent urinary tract infection. Fistula to the vagina (colovaginal fistula) results in stool drainage through the vagina and associated skin irritation and hygienic issues. A fistula to the skin (colocutaneous fistula) causes an abscess in the abdominal wall and a skin opening that drains pus and stool. Fistula may also form between colon and another segment of intestine.

  • Diverticular stricture – when chronic inflammation surrounding the diverticula causes severe scarring and narrowing of the colon, thus obstructing stool passage. Symptoms include abdominal bloating and pain, change in bowel pattern (often more constipated), nausea, decreased appetite.

  • Diverticular bleeding – when blood vessels at the opening of a diverticulum was “scratched” and bleeds. Bleeding is usually brisk and of large amount, bright red and mixed with some blood clots. The sudden blood loss may cause weakness or dizziness, but there is typically no pain.

Diagnosis and treatment of diverticular disease

Diverticulosis may be found on colonoscopy or CT scan done for other reasons and does not need any treatment. When there are symptoms of diverticulitis, stricture or fistula, CT scan usually confirms the diagnosis. Colonoscopy is recommended to exclude other disease processes when it can be safely performed. When diverticulitis is complicated with free perforation or stricture causing severe bowel obstruction, emergency surgery to remove the diseased segment is typically needed and is usually done via an open incision. Sometimes a temporary colostomy (where the end of the healthy bowel is brought out to a skin opening and fecal material is emptied into a bag attached on the skin) may be needed. For diverticulitis with fistula, abscess or multiple recurrent episodes, initial treatment is with antibiotics (and drainage of the abscess if present) to treat the infection and cool off the inflammation, followed by elective surgery to remove the diseased colon segment. Dr. Choi usually performs elective colon resection with laparoscopic (minimally-invasive) technique, and a colostomy is rarely needed. Colonoscopy along with CT scan are used to diagnose and manage diverticular bleeding. Life-threatening bleeding not amenable to colonoscopic or other less invasive treatment may also require emergency resection of the colon.

Helpful links:


*American Society of Colon and Rectal Surgeons