Diverticulitis risk factors: who is more likely to get it

Diverticulosis, diverticulitis and diverticular disease

Diverticulosis is when small pouches, or sacs, form and push outward through weak spots in the wall of the colon, mostly in the lower part called the sigmoid colon. Most people who have these pouches do not have symptoms or problems. Diverticulitis is when the pouches become inflamed; it can come on suddenly and may lead to serious complications. Diverticular disease means the pouches lead to chronic symptoms, diverticular bleeding, or diverticulitis or its complications (NIDDK).

How common it is

Diverticulosis is quite common, especially as people age. More than 30% of US adults aged 50 to 59 and more than 70% of those older than 80 have it. Less than 5% of people with diverticulosis develop diverticulitis. In the United States, about 200,000 people are hospitalized for diverticulitis each year (NIDDK).

Who is more likely to get diverticulitis

Doctors are not sure what causes diverticular disease. NIDDK and MedlinePlus say experts think these factors may play a role in causing it or raising the risk (NIDDK) (MedlinePlus):

• Age. People are more likely to develop diverticulosis and diverticulitis as they age (NIDDK).
• Genes. Research suggests certain genes may make some people more likely to develop diverticular disease (NIDDK).
• A diet low in fiber and high in red meat (NIDDK).
• Lack of physical activity (NIDDK).
• Medicines such as nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids (NIDDK).
• Obesity (NIDDK). You can check your BMI.
• Smoking (NIDDK). See the quit smoking check.

Sex and background also show up in the numbers. Under age 50, diverticulitis is more common in men than in women; from age 50 on, it is more common in women. Research suggests that in the United States diverticulitis is more common in white Americans, and diverticular bleeding is more common in Black Americans, than in other groups (NIDDK).

Scientists are also studying bacteria or stool getting caught in a pouch, changes in the gut microbiome, problems with connective tissue, muscles or nerves in the colon, and immune system problems. These are not proven risk factors (NIDDK).

Symptoms

Most people first notice symptoms when they develop complications, such as bleeding or diverticulitis (NIDDK). Diverticulitis may cause (NIDDK):

• abdominal pain, most often in the lower left side
• constipation or diarrhea
• fevers and chills
• nausea or vomiting

Some people with pouches have chronic bloating, constipation or diarrhea, or cramping or pain in the lower abdomen, even without diverticulitis. Other conditions, such as irritable bowel syndrome, cause similar symptoms, so these symptoms may not mean diverticular disease. NIDDK says to see your doctor if you have them (NIDDK).

Diverticulitis can lead to an abscess, a fistula, a blocked intestine, a hole in the colon (perforation) or an infection of the lining of the abdomen (peritonitis) (NIDDK).

How it is found

Doctors review your history, examine you and order tests: blood tests, a stool test, imaging such as CT, ultrasound or MRI, and sometimes a colonoscopy. A colonoscopy can confirm the diagnosis and rule out other conditions, such as cancer (NIDDK). See colorectal cancer risk factors and the colon cancer screening age check.

Steps that may lower the risk

Research suggests these may lower the risk of developing diverticulitis (NIDDK) (MedlinePlus):

• eating a diet high in fiber and low in red meat
• being physically active on a regular basis
• not smoking, or quitting if you smoke
• reaching and keeping a healthy weight

The Dietary Guidelines for Americans 2020-2025, as quoted by NIDDK, recommend 14 grams of fiber per 1,000 calories, for example 28 grams a day on a 2,000-calorie diet. Your doctor may suggest adding fiber a little at a time (NIDDK). If you had diverticulitis before, NIDDK suggests asking your doctor whether lifestyle changes could lower the chance of it coming back, and whether any medicines you take could raise your risk (NIDDK).

Common questions

Does constipation cause diverticulitis?

NIDDK and MedlinePlus list constipation as a symptom of diverticulitis and of chronic diverticular disease, not as one of its risk factors. The factors they name are age, genes, a low-fiber, high red meat diet, inactivity, NSAIDs and steroids, obesity and smoking (NIDDK) (MedlinePlus).

Should I avoid nuts, seeds and popcorn?

Most people with diverticulosis or diverticular disease do not need to avoid specific foods. Doctors used to advise avoiding nuts, popcorn and seeds, but more recent research suggests they are not harmful. Talk with your doctor about whether to change what you eat (NIDDK).

Can I take ibuprofen for diverticulitis pain?

Ask your doctor. NIDDK says doctors may recommend antispasmodics or acetaminophen instead of NSAIDs, because NSAIDs may increase the chance of diverticulitis complications (NIDDK).

Also see gallstones risk factors and fatty liver disease.