Can Diverticulitis Cause Cancer?

In the United States, more than 30% of people over the age of 50 will develop diverticulosis, a condition marked by small pouches in the colon wall. While the disorder can lead to undesirable side effects, like inflammation, bleeding and constipation, diverticulosis does not appear to cause colon cancer.

Diverticulosis & Colon Cancer

Diverticulosis is characterized by small bulges (or diverticula) that develop in the walls of the intestines, usually in the lower colon. These pockets occur when the inner layer of the intestines pushes outward through weak points in the colon’s outer layer.


In most patients, the presence of diverticula won’t cause any symptoms. But in around 1 out of every 4 patients, a pouch will become inflamed, leading to problems:

  • changes in bowel movements
  • abdominal pain
  • bleeding

These are the symptoms of diverticulitis, which is what doctors call diverticulosis after the condition has caused inflammation and discomfort. Diverticulitis usually happens because a bit of fecal matter has become trapped in one of the pouches, ultimately inflaming the colon wall. In some cases, the formation of diverticula can injure small blood vessels in the intestinal wall and lead to rectal bleeding. This condition is called diverticular bleeding.

As a group of related disorders, diverticulosis, diverticulitis and diverticular bleeding are referred to simply as “diverticular disease.”

What Are The Symptoms Of Diverticulitis?

When diverticula become inflamed, symptoms can range from mild to severe. People who experience an acute onset of symptoms should visit an emergency room immediately, or call an ambulance, since untreated cases of diverticulitis can lead to serious complications.

Symptoms of diverticulitis include:

  • alternating diarrhea and constipation
  • painful tenderness or cramping in the low abdomen
  • chills and fever
  • abdominal bloating
  • nausea and vomiting
  • palpitations (the feeling that your heart is beating too fast)
  • general weakness
  • fatigue

These are considered “non-specific” symptoms, because they don’t give doctors much to go on. As you’ve probably noticed, fatigue, chills and nausea can indicate the presence of numerous different conditions, including the flu. Self-reported symptoms like the ones we listed above, which are common in people with diverticulitis, can’t be considered a sure sign of the disease. Colon cancer, for example, frequently causes diarrhea, constipation, abdominal pain, rectal bleeding and general weakness, all of which could also be signs of a diverticular disease.

Considering the ambiguity of these symptoms, it’s not surprising that colon cancer is often misdiagnosed as a benign case of diverticulitis. Supreme Court Justice Ruth Bader Ginsburg, for instance, was diagnosed with colon cancer in 1999 – but only after being inaccurately diagnosed with diverticulitis.

What Causes Diverticulosis?

Diverticulosis is extremely common in the United States, but almost unheard of in parts of the world where people eat fiber-rich diets. In the developing world, most notably Africa and Asia, people just don’t get diverticulosis. The disease’s prevalence in Africa, for example, has been estimated to be as low as 0.5%.

This striking disparity has led researchers to pose a compelling theory. Diets that are low in fiber, like those in the developed world, often lead to constipation. Constipation in turn leads to increased pressure in the intestines, along with straining during bowel movements. Over a number of years, the combination of elevated pressure and straining causes diverticulosis.

Observational studies have supported this theory with hard evidence. One Harvard study, for example, found that male subjects who consumed the highest amounts of fiber were 42% less likely to develop diverticulitis than men who consumed less fiber.

Is There A Link To Colorectal Cancer?

No. Researchers have been unable to establish any causal association between diverticulitis and cancers of the colon or rectum, although some lifestyle factors may contribute to both conditions. Low-fiber diets, for example, have been shown to increase the risk for both diverticulitis and colon cancers.

In a 2011 study, researchers from Sweden analyzed the hospital records from over 41,000 colon cancer patients to investigate the disease’s potential link to diverticulitis. Each patient – who had been admitted to the hospital for colon cancer between 1992 and 2006 – was matched with two control patients who had never been diagnosed with colon cancer. The question was simple: were colon cancer patients more likely than people without colon cancer to have been treated for diverticular disease? The answer? No. One year after being admitted to a hospital for diverticulitis, patients were no more likely to be diagnosed with colon cancer. Colon cancer mortality was no different between patients with and without diverticulitis.

But since the conditions’ share common symptoms, most doctors will check a patient’s colon for signs of malignancy after an episode of diverticulitis. Double-checking is good medical policy. Diverticulitis can increase the rigidity of intestinal walls, which makes performing a colonoscopy – the primary way doctors diagnose colon cancers – more difficult.

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