Diverticulitis affects an estimated 200,000 people in the United States each year, and the numbers continue to climb — particularly among adults over 40. Understanding the underlying diverticulitis causes can help you recognize risk factors early and make smarter choices for your gut health. Here are 10 key factors that research links to this painful condition.
1. Low-Fiber Diet
A diet consistently low in fiber is one of the most well-established diverticulitis causes. When you don’t eat enough fiber, stool moves slowly through the colon. This sluggish transit creates higher pressure inside the colon walls, which can lead to the formation of small pouches called diverticula. Over time, these pouches may become inflamed or infected. According to PubMed, low dietary fiber intake prevalent in Western diets is a central focus in the development of diverticular disease. Aim for 25 to 30 grams of fiber daily from fruits, vegetables, and whole grains to support healthy digestion.
2. High Red Meat Consumption
Eating large amounts of red meat appears to significantly increase your risk. Research suggests that red meat may promote inflammation in the gut lining and alter the balance of bacteria in the colon. As noted by the NIH, high red meat intake is a recognized risk factor for diverticulosis, which is the precursor to diverticulitis. Some studies indicate that men who eat the most red meat have a notably higher chance of developing symptomatic diverticular disease. Replacing a few weekly servings of red meat with fish, poultry, or plant-based protein is a practical step toward lowering your risk.
3. Obesity and Excess Body Weight
Carrying excess weight, particularly around the midsection, puts additional strain on the digestive system. Clinical evidence shows that obesity increases both the risk of developing diverticulitis and the likelihood of complications like perforation or abscess. The connection may involve chronic low-grade inflammation that accompanies excess fat tissue. Maintaining a healthy weight through balanced eating and regular movement can reduce pressure on the colon and support overall digestive health.
4. Aging and Structural Changes in the Colon
Age is one of the strongest predictors. As you get older, the muscular wall of the colon naturally loses some of its elasticity and strength. These structural changes make it easier for diverticula to form at weak spots. According to PubMed, structural colonic wall abnormalities play a key role in the development of diverticular disease. While you can’t stop aging, staying physically active and eating a fiber-rich diet may help slow these changes and keep flare-ups at bay.
5. Smoking
Smoking does more than harm your lungs — it also affects your gut. Studies indicate that smokers face a higher risk of diverticulitis compared to nonsmokers. Tobacco use may damage the blood vessels supplying the colon wall, weakening tissue integrity over time. It can also impair immune function in the gut, making it harder for your body to fight off localized infections in diverticula. Quitting smoking is one of the most impactful steps you can take for both your digestive and overall health.
6. Sedentary Lifestyle
Spending most of your day sitting or inactive may contribute to sluggish bowel motility. Regular physical activity helps stimulate the natural contractions that move waste through your colon efficiently. Without that movement, pressure can build in the colon walls. Research suggests that vigorous exercise, in particular, appears to have a protective effect against diverticular disease. Even moderate activities like brisk walking for 30 minutes most days of the week may help lower your risk.
7. Gut Microbiota Imbalances
The trillions of bacteria living in your colon play a crucial role in digestive health. When this microbial community falls out of balance — a condition called dysbiosis — inflammation may increase. As highlighted in PubMed, alterations in the gut microbiota are considered a contributing factor in the development of diverticulitis. Fecal obstruction of diverticula can encourage bacterial overgrowth, triggering the inflammatory response. Eating probiotic-rich foods like yogurt and fermented vegetables may help support a healthier microbial environment in the gut.
8. Regular NSAID Use
Over-the-counter painkillers like ibuprofen and aspirin are common household staples. However, frequent use of nonsteroidal anti-inflammatory drugs, or NSAIDs, has been linked to a higher risk of diverticulitis and its complications. These medications can irritate the lining of the digestive tract and may increase the chance of perforation in existing diverticula. The NIH identifies NSAIDs as a notable risk factor for diverticulitis development. If you rely on NSAIDs regularly, talk to your doctor about alternative pain management strategies.
9. Excessive Alcohol Consumption
Heavy drinking can take a toll on your entire digestive system. Alcohol irritates the intestinal lining and may disrupt the balance of gut bacteria, both of which can contribute to inflammation. Clinical evidence suggests that excessive alcohol intake is associated with an increased risk of diverticulitis flare-ups. Alcohol can also interfere with nutrient absorption, potentially worsening the effects of a low-fiber diet. Limiting alcohol to moderate levels — one drink per day for women and two for men — is a sensible guideline for gut health.
10. Genetic Predisposition
Your genes may play a larger role than previously thought. Emerging research suggests that genetic factors can influence the structure of your colon wall and how your body handles inflammation. If close family members have experienced diverticular disease, your own risk may be elevated. Twin studies have estimated that genetics could account for roughly 40 to 50 percent of susceptibility. While you can’t change your DNA, being aware of your family history allows you to be proactive with screening, dietary choices, and lifestyle habits.
Understanding diverticulitis causes empowers you to take meaningful steps toward prevention. Many of the risk factors on this list — from diet and exercise to smoking and medication use — are within your control. Start with one change this week, whether it’s adding more fiber to your meals or scheduling a conversation with your doctor about your personal risk profile.
Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making health decisions.
