Diverticulosis and Diverticulitis

Diverticulosis is a condition where small pouches protrude outwardly from the colon. These pouches, called diverticula, are formed by increased pressure from gas, waste, or liquid on weakened spots in the colon’s lining. Diverticulosis is very common in Western populations, with the main cause being a low-fiber diet, and is more common in men and people over the age of 40. Diverticulosis has no symptoms unless diverticula bleed or become inflamed or infected, a condition known as diverticulitis.

Symptoms of Diverticulitis

Diverticulosis typically has no symptoms. Symptoms of diverticulitis include:

  • Persistent lower abdominal pain
  • Abdominal tenderness
  • Bleeding from the rectum
  • Constipation
  • Cramps and/or diarrhea
  • Fever
  • Nausea and/or vomiting
  • Painful urination

Causes of Diverticulitis

There is no proven cause for diverticulosis. Physicians believe that recurrent pressure in the colon due to muscle spasm or straining may cause diverticula to form at weak spots in the colon wall. There also appears to be a genetic predisposition for diverticulosis. Risk factors for diverticulosis becoming diverticulitis include: age over 60, obesity, smoking, a low fiber diet, chronic constipation and certain medications. 

Diagnosis of Diverticulosis and Diverticulitis

Diverticulosis is generally discovered when a physician notices pouches in the colon wall while performing routine tests such as an X-ray, colonoscopy or CT scan. A gastroenterologist will then complete a physical exam, inquire about your medical history, and depending on your symptoms, may order diagnostic tests to rule out diverticulitis, an inflammation of a diverticulum.

  • Blood tests: Tests for signs of inflammation or anemia.
  • Colonoscopy: A small tube with a video camera at one end is passed through the anus and rectum.
  • CT scan: Computerized tomography can identify diverticulosis, diverticulitis, and bowel obstructions or other changes in the intestines.
  • Fecal tests: Rule out infection, inflammation, or blood in the stool.
  • Lower GI series: A barium enema uses X-rays and a chalky liquid substance that coats your digestive tract to visualize deformities such as strictures, obstructions, diverticula or fistulas within the large intestine.

Treatment of Diverticulosis and Diverticulitis

Managing diverticulosis includes a high-fiber diet or fiber supplements, adequate daily fluid intake, and avoidance of constipation. Mild diverticulitis can be treated with rest, changes in your diet, and with or without antibiotics. Severe or recurring diverticulitis resulting in peritonitis, abscess, obstruction, fistula formation into contiguous organs to include the small bowel, bladder, or vagina, or other complications may require surgery. Your physician will review your symptoms and work with you to decide on a treatment plan that is best for you.

Dietary and Lifestyle Changes

  • Medications: Minimize use of steroids, narcotics, and nonsteroidal anti-inflammatory drugs (NSAIDs), which are linked to an increased risk of diverticulitis.
  • Diet: A diet low in animal fat, with plenty of water and fiber, such as fresh fruits, vegetables, and whole grains, helps prevent constipation, maintain normal gut flora, and may make it easier for food waste to pass through the colon.
  • Exercise: Staying active promotes normal bowel function and reduces pressure in the colon. Losing weight, if obese, lowers risk of diverticulitis.
  • Smoking: Smoking cigarettes or vaping with nicotine may increase the chances of diverticulitis.


  • Acetaminophen is the recommended medicine for pain relief as NSAIDs should be avoided to decrease the risk of internal bleeding.
  • Antibiotics can be prescribed orally or given intravenously in order to treat infection.
  • Probiotics are live bacteria similar to those that occur naturally in the small and large intestine, which have been believed to decrease the risk of diverticulitis.


Studies indicate that patients who have two or more episodes of diverticulitis may benefit from surgery.

  • Colon resection is when surgeons remove the affected part of the colon laparoscopically or with open surgery, and join the remaining ends together, allowing for normal bowel movements.
  • Temporary colostomy is used in cases where there is too much inflammation to rejoin your colon and rectum. A surgeon may perform a colostomy — an opening in the abdominal wall connected to the colon for stool to pass into a bag. Once inflammation has improved, the surgeon can rejoin the ends of the colon and close the opening in the abdomen.
  • Interventional radiology embolization is a minimally-invasive surgical technique used to stop or control diverticular bleeding.
  • Endoscopic control using clips, injection therapy, or thermal treatment are also amenable ways to end diverticular bleeding.

If you would like to consult with a provider, schedule an appointment with Virginia Mason's Gastroenterology Department by calling (206) 223-2319.