Diverticulosis and diverticulitis are two conditions that occur in your large intestine (also called your colon). Together they are known as diverticular disease. Both share the common feature of diverticula. Diverticula are one or more pockets or bulges that form in the wall of your colon.
Diverticula are like expanded areas or bubbles that form when you fill the inner tube of a bike tire with too much air. The increase in pressure from too much air being pumped into the inner tube causes the bubble to form where the rubber is the weakest. Similarly, an increase in pressure inside the colon causes pockets or bulges (diverticula) to form in weakened areas of your colon’s walls.
Diverticula can range from pea-size to much larger. Although they can form anywhere in the inner lining of your colon, they are most commonly found in your lower left-side, in the S-shaped segment of your colon called the sigmoid colon.
Diverticulosis is simply the presence of these tiny bulges or pockets (diverticula) in your colon. They usually don’t cause any symptoms or need to be treated. However, diverticulosis can lead to diverticulitis.
Diverticulitis is inflammation (swelling) and infection in one or more diverticula. You may feel pain, nausea, fever and have other symptoms. This is a much more serious and potentially dangerous condition.
Diverticulosis is very common in Western populations and occurs in 10% of people over age 40 and in 50% of people over age 60. The rate of diverticulosis increases with age, and it affects almost everyone over age 80.
You are at increased risk of diverticular disease (diverticulosis or diverticulitis) if you:
Scientists aren’t really sure what causes diverticulosis, but they think it’s caused by not eating enough fiber. Not eating enough fiber causes a buildup of waste (constipation) in your colon. Constipation puts extra strain on the walls of the colon. This increased pressure causes the little pockets — the diverticula — to form in weak areas in your colon.
Again, scientists aren’t sure what causes diverticulitis, but they think the infection starts due to the bacteria in stool that gets pushed into the diverticula. Another theory is that the walls of the diverticula itself erode from the increased pressure on the colon walls.
Usually diverticulosis does not cause any troublesome symptoms. However, some people report:
Keep in mind that having one or more of these symptoms doesn’t mean you have diverticulosis. These symptoms are common symptoms of other gastrointestinal disorders such as irritable bowel syndrome, celiac disease, inflammatory bowel disease, appendicitis, gallstones and stomach ulcers.
The symptoms of diverticulitis include:
Because most people with diverticulosis don’t have symptoms, it’s usually found from other tests that are done for an unrelated reason.
If you have symptoms of diverticulitis, it’s important to be seen by your healthcare provider to get the correct diagnosis.
First, your healthcare provider will ask you about your medical history including your current symptoms, the types of foods you normally eat, how often you have bowel movements and other questions about your bowel movements, and will review any medications you are currently taking. Your healthcare provider will check your abdomen for pain and tenderness.
Other tests that may be performed or ordered to help diagnose your condition include:
If you have diverticulosis, you likely don’t have symptoms and don’t need treatment. However, since diverticulosis could lead to diverticulitis, you should eat a diet high in fiber as a preventive measure. This means eating more fruits, vegetables, grains, nuts, seeds, beans, legumes and less red meat.
If your diverticulitis is mild, your healthcare provider will prescribe an oral antibiotic, such as metronidazole (Flagyl®), trimethoprim-sulfamethoxazole (Bactrim®), ciprofloxacin (Cipro®) or amoxicillin and clavulanic acid (Augmentin®). Rest, taking over-the-counter medications for pain and following a low-fiber diet or a liquid diet may be recommended until your symptoms improve. Once your symptoms improve, you can slowly return to soft foods, then a more normal diet, which should be one that includes many high-fiber foods. You and your healthcare provider will discuss the specifics of your treatment plan.
If your diverticulitis is severe, you have rectal bleeding or are having a repeat bout of diverticulitis, you may be admitted to the hospital to receive intravenous (IV) antibiotics, IV fluids or possibly be considered for surgery.
Surgery for diverticulitis is considered if you have:
Surgery usually involves removing part of the colon. During surgery, the diseased section of the colon is removed and the colon is reattached to the rectum.
Depending on the extent and severity of disease, surgery can be performed in a single surgery, in two surgeries, in an open procedure (tradition surgery performed through a large incision) or by a minimally invasive laparoscopic procedure (surgery performed through small holes in your abdomen). You may or may not need a colostomy. A colostomy involves bringing the healthy end of your colon to the surface of your skin through a hole made in your abdominal wall. A colostomy bag attaches to the colon on the surface of your skin to collect colon waste. The colostomy bag may be needed for several months while your colon heals. Once healed, the colon is reattached to the rectum (at which time the colostomy bag is removed).
You and your surgeon will discuss the details of your specific surgery including risks, complications and what to expect after surgery.
Having regular bowel movements and avoiding constipation and straining is important to prevent diverticular disease and reduce its complications.
To accomplish this:
The National Institute of Diabetes and Digestive and Kidney Disease recommends eating 14 grams per 1,000 calories consumed per day. For example, if you follow a 2,000 calorie diet every day, you should try to eat 28 grams of fiber each day. Every person, regardless of whether they have diverticula, should try to consume this much fiber every day. Fiber is the part of plant foods that can’t be digested.
High-fiber foods include:
Besides preventing constipation, eating a high-fiber diet helps lower blood pressure, reduces blood cholesterol, improves blood sugar and reduces the risk of developing certain intestinal disorders such as colorectal cancer.
For more tips and food examples of high-fiber foods, visit:
Until recently, your healthcare provider may have told you to avoid eating nuts, seeds, corn and popcorn. Newer research shows that these foods do not appear to cause flare-ups.
What’s most important is to figure out what foods do and don’t cause symptoms and avoid the foods that cause symptoms or make your symptoms worse.
If you’ve been told you have diverticulosis, this is usually not cause for concern. This condition is very common and increases with age. It is present in about 50% of people over age 60 and in almost everyone over age 80. You likely won’t even have symptoms if you have diverticulosis. If you have a mild case of diverticulosis, it may go away on its own without treatment.
Up to 30% of people with diverticulosis do develop diverticulitis. Between 5% and 15% will develop rectal bleeding.
Most people who have diverticulitis will recover with about a seven to 10-day course of antibiotics and rest. Severe complication of diverticulitis occur in about the following percent of people: perforation of the colon (1% to 2% of patients), obstruction (rare), fistula (14%) or abscess (30%).
The best self-treatment is to eat a high-fiber diet (one filled with fruits and vegetables, cereals and whole grains, nuts, beans and legumes. Also, drink more fluids (half your body weight in ounces each day) and exercise (helps speed waste through your colon).
Diverticulitis can be a serious, and even a potentially life-threatening complication. Health problems that can arise from diverticulitis include:
(These health problems are more fully explained earlier in this article.)
If you’ve had a previous episode of diverticulitis, you have up to about a 20% chance of having a repeat episode. However, fewer than 6% of patients will develop complicated disease or need emergency surgery.
Diverticulitis can be treated and be healed with antibiotics. Surgery may be needed if you develop complications or if other treatment methods fail and your diverticulitis is severe. However, diverticulitis is generally considered to be a lifelong condition.
If the affected area of your colon is removed, another surgery is usually not needed. The most common location for diverticulitis is the sigmoid colon, which is the S-shaped near end portion of your colon. Although this is the most common location, it’s possible for diverticula to form in other areas of your colon. Because each person is different, be sure to ask your healthcare provider, surgeon, or colon specialist about your risk for return appearance of diverticulitis.
Call your healthcare provider:
Yes, you can take a fiber supplement. Available products include FiberCon®, Citrucel®, Metamucil® and generics of these branded products and other fiber products. Be sure to drink at least 8 ounces of liquids with your supplement.
Some researchers believe not having the proper balance of “good bacteria” in your gut may play a role in the development of diverticulitis. However, right now, there’s not enough scientific evidence to prove that probiotics can help prevent diverticulitis. Probiotics may be helpful in preventing constipation however.
Visit our Butts & Guts Podcasts page to learn more about digestive conditions and treatment options from Cleveland Clinic experts.
Last reviewed by a Cleveland Clinic medical professional on 04/01/2020.