Diverticulosis is the condition of having small pouches, called diverticula, in the walls of your colon. The inner lining of the intestine pushes outward through weak spots in the outer muscular wall, forming tiny balloon-like pockets. It’s extremely common, especially with age, and the vast majority of people who have it never know because it causes no symptoms. About 80% to 85% of people with diverticulosis remain completely asymptomatic throughout their lives.
How Common Is Diverticulosis?
Diverticulosis becomes increasingly prevalent as you get older. More than 50% of people over 60 have diverticula in their colon, and by age 80, that number rises to around 70%. Most people discover they have it incidentally, during a colonoscopy or imaging test performed for an unrelated reason. It’s so routine that many gastroenterologists consider it a normal part of aging rather than a disease in itself.
Why Diverticula Form
The colon wall isn’t uniformly strong. There are natural weak points where blood vessels penetrate the muscle layer, and over time, pressure inside the colon can push the lining outward through these spots. Several factors increase the likelihood of this happening.
Low fiber intake is one of the most well-established contributors. Fiber adds bulk to stool and helps it move through the colon more easily, which reduces the internal pressure that drives pouch formation. Higher fiber intake is associated with a 14% lower risk of developing diverticular complications. On the flip side, diets high in red and processed meat are linked to a 9% increased risk.
Body weight plays a significant role. Compared to people with a healthy BMI, those who are overweight face a 32% higher risk, and those who are obese are 44% more likely to develop problems. Physical activity matters too: higher activity levels are associated with a 16% reduced risk. Smoking, whether current or past, raises the risk by 13% to 17%.
Genetics also contribute. Researchers have identified a cumulative genetic risk score for diverticular disease, and for each unit increase in that score, the risk rises by 58%. This genetic influence is particularly strong in people under 60. That said, lifestyle factors reduce risk regardless of genetic susceptibility, meaning your habits still matter even if diverticular disease runs in your family.
Symptoms (or Lack of Them)
Most people with diverticulosis feel nothing at all. The pouches sit quietly in the colon wall without causing pain, bloating, or changes in bowel habits. When diverticulosis is found on a colonoscopy, it typically requires no treatment and no follow-up specifically for the diverticula themselves.
Some people with diverticulosis do report mild, nonspecific symptoms like occasional cramping, bloating, or irregular bowel patterns. These can be difficult to distinguish from irritable bowel syndrome or other common digestive issues, and having diverticula doesn’t necessarily mean they’re the cause of the discomfort.
Diverticulosis vs. Diverticulitis
This is the distinction most people want to understand. Diverticulosis simply means the pouches exist. Diverticulitis means one or more of those pouches has become inflamed or infected, which causes real symptoms: sharp pain (usually in the lower left abdomen), fever, nausea, and changes in bowel habits. Only about 5% of people who have diverticulosis ever go on to develop diverticulitis. The two terms describe different stages of the same underlying condition, but having diverticulosis does not mean diverticulitis is inevitable or even likely.
Possible Complications
The most notable complication of diverticulosis, aside from diverticulitis, is bleeding. Blood vessels run along the walls of the diverticula, and over time they can weaken and rupture. Diverticular bleeding often shows up as sudden, painless, bright red or maroon-colored blood in the stool. It can look alarming, but in many cases it stops on its own. When it doesn’t, a gastroenterologist can locate the bleeding vessel during a colonoscopy and seal it using specialized tools. Recurrent bleeding is possible, so anyone who has experienced one episode should be aware it could happen again.
How Diverticulosis Is Found
Because diverticulosis rarely causes symptoms, it’s almost always discovered during a procedure done for another reason. A colonoscopy is the most common way. The gastroenterologist can directly see the small openings of the pouches along the colon wall. Sometimes diverticula are spotted on a CT scan ordered for abdominal pain or another concern. There’s no screening test specifically for diverticulosis, and none is needed, since the condition by itself is considered benign.
Managing Diverticulosis With Diet
The primary recommendation for people with diverticulosis is to eat a high-fiber diet. Adults should aim for about 14 grams of fiber per 1,000 calories consumed, which works out to roughly 28 grams per day on a standard 2,000-calorie diet. Good sources include beans, lentils, whole grains, fruits, vegetables, and nuts. If your current fiber intake is low, it helps to increase it gradually over a few weeks so your digestive system can adjust without excessive gas or bloating.
For years, doctors told patients with diverticulosis to avoid nuts, seeds, and popcorn, fearing these foods could lodge in the pouches and trigger inflammation. That advice has been abandoned. There’s no evidence that these foods increase the risk of diverticulitis, and some high-fiber options like nuts and seeds may actually be protective.
Beyond fiber, the broader lifestyle picture matters. Maintaining a healthy weight, staying physically active, limiting red and processed meat, and not smoking all reduce the chances of diverticulosis progressing to something more serious. These are the same habits that lower risk for heart disease and several cancers, so the benefits extend well beyond your colon.