Diverticulosis vs. Diverticulitis: What's the Difference

The thing about gut health is, there are many conditions that affect it., and, they all present pretty similarly—abdominal pain and change in bowel habits. Diverticulitis is one of those conditions—but it can sometimes be confused with something called diverticulosis, which can be a precursor to diverticulitis.

Though these two conditions have similar names—and one can lead to the other—it's important to be able to distinguish between the two.

Right up front, the names of the conditions themselves can offer essential clues: the suffix "osis"—as in diverticulosis—denotes a condition or disease; the suffix "itis"—as in diverticulitis—references the presence of inflammation.

What Is Diverticulosis?

First things first. In order to understand a diagnosis of diverticulosis, you have to know a bit about the colon—the large intestine or large bowel. Sometimes, tiny pouches can form in your gastrointestinal tract—usually in the lower part of the colon called the sigmoid colon, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). These pouches—called diverticula—can push through weak spots of the wall of your colon—that's called diverticulosis.

For many people, those diverticula don't cause issues. In fact, many people live with diverticulosis without any complications. Per the NIDDK, more than 30% of adults between the ages of 50 and 59 have the condition—that number rises to 70% in people over 80 years old. But "fewer than 5% of people with diverticulosis will ever have a problem," Lisa Strate, MD, a gastroenterologist, researcher, and professor of medicine at the University of Washington in Seattle, tells Health.

Because diverticulosis itself doesn't present symptoms, it's most often found during routine colonoscopies, according to a recent review article in Mayo Clinic Proceedings. It may also show up on radiological exams, like abdominal CT scans, another recent review in Nature Reviews Disease Primers points out.

But again: Many people with diverticulosis won't develop symptoms or problems from the condition—when they do, and when the diverticula become inflamed, that's known as diverticulitis.

What Is Diverticulitis?

Diverticulitis means one or more diverticula in the colon wall have become inflamed or infected. According to the American Gastroenterological Association (AGA), it often comes on quickly and can cause symptoms such as abdominal pain—usually on the lower left side—stomach cramping, bowel changes like constipation or diarrhea, chills, and fever.

The NIDDK says about 200,000 people are hospitalized with diverticulitis each year, but diverticulitis is only one part of diverticular disease, which is when diverticula cause chronic symptoms, or when someone experiences diverticular bleeding, diverticulitis, or complications from diverticulitis.

While diverticular bleeding speaks for itself (it's when a small blood vessel within the wall of the diverticulum pouch bursts, and can cause life-threatening blood loss), complications from diverticulitis can look like the following, per the NIDDK:

• An abscess in the colon
• Fistula—an abnormal connection between two body parts, like the bowel and bladder or vagina
• Intestinal obstruction
• Perforated colon
• Peritonitis—an infection in the abdominal cavity

While people are more likely to develop the diverticular disease as they age, experts aren't entirely sure what else causes the condition. Per the NIDDK, the following factors can increase a person's risk of developing the disease:

• Diet: A typical American (or "Western") diet—one that's high in red meat, fat, and refined grains—has been linked to an increase in diverticulitis. On the other hand, high fiber intake and dietary patterns that are plentiful in fruits, vegetables, and whole grains are associated with a lower risk of this GI condition.
• Obesity: Being significantly overweight, particularly if you carry excess weight around your middle, is associated with an increased risk of diverticulitis.
• Physical inactivity: Experts believe a sedentary lifestyle is a risk factor too. "The more physical activity someone does, the less likely they are to develop diverticulitis," Dr. Strate points out.
• Smoking: Not only is smoking linked to a greater incidence of diverticulosis but it's also linked to complications such as diverticulitis. Per the Mayo Clinic: "People who smoke cigarettes are more likely than nonsmokers to experience diverticulitis."
• Certain medications: Regular use of corticosteroids, opiates, and non-steroidal anti-inflammatory drugs (NSAIDs) is associated with a greater risk of diverticulitis.

Prevent Diverticulosis From Turning Into Diverticulitis

Experts don't know exactly how many people with diverticulosis will develop symptoms if they do not have diverticulitis, the NIDDK says—and most people don't know they have diverticulosis until they experience an initial episode of diverticulitis.

If you have had a diverticulitis flare before—which your doctor may try to clear up with antibiotics, a clear liquid diet, and pain medication—it's likely that your main goal is not to have another one. The AGA, NIDDK, and Mayo Clinic suggest the following measures to help prevent a recurrence:

• Adopt a high-fiber diet: Slowly start increasing your fiber intake by eating more plant-based foods, including fruits, vegetables, whole grains, and legumes.
• Hydrate: You need plenty of liquids to replace the fluids absorbed by the fiber in your diet. Otherwise, you may end up constipated.
• Be physically active: Vigorous, heart-pumping exercise may be particularly helpful.
• Quit smoking: For several health reasons and because it's expensive and no longer socially acceptable.
• Achieve or maintain a healthy weight: Obesity is strongly linked to diverticulitis.
• Avoid using NSAIDS: Unless it's advised by a doctor, try not to use pain relievers (aspirin, ibuprofen, and naproxen to name a few) two or more times a week.

It really boils down to living a healthy lifestyle, Dr. Strate points out: "A healthy lifestyle is protective against so many things—diabetes, heart disease—that it makes sense for people to try and aim for that."