Most people with diverticulosis have no symptoms at all. The condition, which involves small pouches forming in the lining of the colon, affects roughly half of adults over 50 and up to 70% of people over 80. It’s typically discovered by accident during a colonoscopy or imaging study done for an unrelated reason.
That said, diverticulosis can occasionally cause noticeable problems, and knowing what to watch for helps you distinguish harmless pouches from something that needs attention.
Why Most People Never Notice It
Diverticulosis is one of the most common findings on routine colonoscopies, yet the vast majority of people who have it will go their entire lives without a single symptom. The pouches themselves are just structural changes in the colon wall. They don’t cause pain, don’t interfere with digestion, and don’t require treatment. Only 1% to 4% of people with diverticulosis ever develop diverticulitis, the inflammatory complication most people worry about.
Because it’s so rarely problematic, screening specifically for diverticulosis isn’t recommended. If you’ve been told you have it after a colonoscopy or CT scan, that’s a normal finding for your age group, not a diagnosis that demands action.
Symptoms Some People Report
There’s a condition sometimes called symptomatic uncomplicated diverticular disease, where people with known diverticulosis experience chronic abdominal discomfort, bloating, or changes in bowel habits without any sign of infection or inflammation. However, this diagnosis is controversial. A large U.S. study found no association between having diverticulosis and experiencing abdominal pain lasting more than 24 hours, and no link to irritable bowel syndrome symptoms either.
In other words, if you have diverticulosis and also experience bloating or abdominal pain, the diverticulosis may not be the cause. Those symptoms could stem from something else entirely, such as irritable bowel syndrome, food intolerances, or other digestive conditions that happen to coexist with the pouches.
Diverticular Bleeding
The one symptom directly tied to diverticulosis (rather than diverticulitis) is bleeding. A blood vessel near one of the pouches can erode and rupture, causing sudden, significant rectal bleeding. This is painless in most cases, which distinguishes it from many other causes of blood in the stool.
The blood is typically dark red or appears as bright red clots. The volume can be alarming. Unlike a small streak of blood from a hemorrhoid, diverticular bleeding tends to produce a large, obvious amount. It often stops on its own, but the sheer volume means it warrants prompt medical evaluation. If you pass a large amount of blood from the rectum without any accompanying belly pain, diverticular bleeding is one of the more likely explanations, especially if you’re over 50.
Regular use of aspirin or anti-inflammatory painkillers like ibuprofen raises the risk of diverticular bleeding. In a study following 47,000 men over 22 years, regular aspirin use increased the risk of diverticular bleeding by about 70%, and regular NSAID use raised it by a similar margin. If you have known diverticulosis and take these medications frequently, that’s worth discussing with your doctor.
How Diverticulitis Feels Different
Diverticulosis itself is the presence of pouches. Diverticulitis is what happens when bacteria multiply inside one of those pouches, causing infection and inflammation. The symptoms are unmistakable and quite different from the vague discomfort sometimes blamed on diverticulosis alone.
Diverticulitis typically causes steady, significant pain in the lower left side of the abdomen. The pain doesn’t come and go like gas cramps. It persists, often worsening over hours. You may also develop fever, nausea, and a noticeable change in bowel habits (constipation or diarrhea). The area may feel tender to the touch. This is an acute illness that feels like being sick, not just uncomfortable.
If you’ve been living with diverticulosis and suddenly develop persistent left-sided abdominal pain with fever, that’s a different situation from the pouches sitting quietly in your colon. Diverticulitis is diagnosed with a CT scan and requires treatment, while diverticulosis on its own does not.
What You Can Do With Diverticulosis
Since diverticulosis rarely causes symptoms, the main goal is reducing the small chance it progresses to diverticulitis or bleeding. The most consistent recommendation is eating enough fiber. 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. Most people fall well short of that. Fruits, vegetables, beans, whole grains, and lentils are the simplest ways to close the gap.
If you’re not used to eating much fiber, increasing your intake gradually over a few weeks helps avoid the gas and bloating that come with a sudden change. Drinking plenty of water alongside the fiber keeps things moving smoothly.
The old advice to avoid nuts, seeds, and popcorn has been largely abandoned. There’s no good evidence that these foods get trapped in diverticula or trigger problems. You don’t need to restrict your diet beyond making sure you’re getting enough fiber overall.