# Understanding & Managing Diverticulitis **Prepared by:** Pedro Cheung MD **Last Updated:** May 2026 > **Important:** This handout provides general health education based on current medical research. It is not a substitute for advice from your personal physician or healthcare provider. Always follow the specific instructions given to you by your care team. --- ## What Is Diverticulitis? Your colon (large intestine) can develop small, balloon-like pouches in its wall called **diverticula**. When these pouches are present but cause no symptoms, the condition is called **diverticulosis** — an extremely common finding, affecting more than half of adults over age 60. Most people with diverticulosis never have any problems. **Diverticulitis** occurs when one or more of these pouches becomes inflamed or infected. It is a common but serious condition, accounting for approximately **200,000 hospital admissions per year** in the United States and more than $6.3 billion in annual healthcare costs.[^1] ### Types of Diverticulitis |Type|What it means|Typical treatment| |---|---|---| |**Uncomplicated**|Inflammation without abscess, perforation, or fistula|Rest, diet change, pain control; antibiotics only when indicated| |**Complicated**|Involves abscess, perforation, bowel obstruction, or fistula|IV antibiotics; possible drainage or surgery| --- ## Common Symptoms - **Lower-left abdominal pain** (most common) — may be sudden or build over days - Nausea and vomiting - Fever and chills - Change in bowel habits (constipation or diarrhea) - Bloating and gas - Loss of appetite > **Go to the ER or call 911 if you have:** severe, rapidly worsening abdominal pain; high fever (above 101°F/38.3°C); inability to keep fluids down; blood in your stool; or signs of shock (rapid heartbeat, dizziness, fainting). --- ## Part 1: Managing the Acute Flare-Up (Active Episode) During an active attack, the primary goal is to **rest your bowel**, reduce inflammation, and allow healing. Your diet during this phase will look very different from your everyday eating. ### Step 1: Clear Liquid Diet (Severe Flare / First 1–2 Days) If your symptoms are severe, your doctor may recommend starting with a **clear liquid diet** to give your digestive tract complete rest.[^2] This means no solid food whatsoever. **Allowed on a clear liquid diet:** - Clear broth (chicken, beef, vegetable — low sodium preferred) - Water, ice chips - Plain gelatin (Jell-O) — no fruit pieces - Popsicles/ice pops — no cream or milk-based - Clear apple juice, grape juice, cranberry juice (no pulp; avoid orange juice) - Sports drinks (Gatorade, Pedialyte) for electrolytes - Plain tea or black coffee (no milk) > ⚠️ **Do not stay on a clear liquid diet for more than 2–3 days** without medical guidance. Extended liquid-only diets can cause malnutrition, muscle loss, and weakness.[^2] --- ### Step 2: Low-Fiber / GI Soft Diet (Days 2–7, or as Symptoms Improve) As pain and fever begin to ease, transition to a **low-fiber diet** (typically 8–12 grams of fiber per day). This allows the colon to continue healing while providing needed nutrition.[^3] **The goal: easy-to-digest foods that don't stimulate the bowel** #### ✅ Foods to Include **Grains & Starches:** - White rice, plain pasta, white bread, plain crackers (saltines) - Plain white tortillas - Low-fiber cereals (Cream of Wheat, plain puffed rice, Corn Flakes) **Fruits (low-fiber options):** - Canned peaches, pears, or fruit cocktail (in juice, drained) - Applesauce (no skin or seeds) - Ripe banana - Soft, ripe cantaloupe or honeydew (no skin) - _(Avoid raw fruit and fruits with skins or seeds during this phase)_ **Vegetables:** - Well-cooked, skinless carrots, green beans, yellow squash - Canned vegetables (drained and rinsed) - Peeled potatoes (no skin) - _(Avoid raw vegetables, broccoli, cabbage, corn, peas, and spinach during this phase)_ **Proteins:** - Eggs (scrambled, poached, or boiled) - Well-cooked fish and chicken (baked, poached — no skin) - Tofu (soft or silken) - Smooth peanut butter (2 tbsp) - Lean ground meat (well-cooked) **Dairy:** - Milk (skim, 1%, or 2%) - Plain yogurt or Greek yogurt (no granola, nuts, or fruit pieces) — **excellent for protein and calcium** - Cottage cheese - Mild cheeses (string cheese, American, Swiss) - Low-fat ice cream or sherbet **Beverages:** - Water (aim for at least 8 cups/64 oz daily) - Diluted fruit juice - Broth - Tea, coffee --- #### ❌ Foods to Avoid During a Flare - **High-fiber foods:** whole grains, bran, raw fruits and vegetables, dried beans, lentils, nuts, seeds - **Fried foods and greasy meals** - **Red meat and processed meats** (hot dogs, sausage, salami) - **Spicy foods** - **Alcohol** - **Carbonated beverages** (may worsen gas and bloating) - **Dairy with added ingredients** (flavored yogurts with seeds, nut-topped cereals) --- ### Pain Management During a Flare - **Acetaminophen (Tylenol®)** is the preferred over-the-counter pain reliever during an acute attack. - **Avoid NSAIDs** (ibuprofen/Advil/Motrin, naproxen/Aleve, aspirin in pain-relief doses) during and after a flare. These medications can irritate the intestinal lining and have been linked to increased risk of complications.[^4] [^5] Talk to your doctor before stopping any prescribed medications. - **Heating pads** on low setting applied to the abdomen may provide comfort. - Rest as much as possible — avoid strenuous activity during an active flare. --- ### What About Antibiotics? You may have received a prescription for antibiotics. **Important new research** has changed thinking in this area: Two large, high-quality randomized clinical trials found that **antibiotics did not speed recovery** and did not prevent complications or recurrence in people with **mild, uncomplicated diverticulitis** who have a normal immune system.[^6] [^7] The American Gastroenterological Association (AGA) now recommends antibiotics be used **selectively, not routinely**, in otherwise healthy adults with mild uncomplicated diverticulitis.[^5] However, antibiotics **are strongly recommended** if you have: - High fever or signs of infection/sepsis - Increasing or high white blood cell count - Immunosuppression (chemotherapy, organ transplant, high-dose steroids) - Complicated diverticulitis (abscess, perforation) - Significant medical conditions (cirrhosis, chronic kidney disease, heart failure, poorly controlled diabetes) - Age over 80 years - Pregnancy **If your doctor prescribed antibiotics:** Take every dose as directed and complete the full course, even if you feel better sooner. Never stop antibiotics early without consulting your provider. --- ## Part 2: The Recovery Phase (Weeks 1–4 After Flare Resolves) Once symptoms have improved — typically within 2–7 days of treatment — you will gradually reintroduce fiber and return to a normal diet. **This transition is critically important**: reintroducing fiber too quickly can cause cramping and bloating, while staying too long on a low-fiber diet delays healing. ### Reintroducing Fiber: A Gradual Approach Start adding **5–15 grams of fiber per day** back into your diet as symptoms allow. Increase slowly over several weeks until you reach the target of **25–35 grams of fiber daily**.[^3] **Add these foods back progressively:** |Week|Fiber Goal|Sample Additions| |---|---|---| |Week 1–2|10–15g/day|Soft-cooked vegetables, ripe fruits without skins, oatmeal| |Week 2–3|15–25g/day|Whole grain bread, canned beans, more vegetables| |Week 3–4|25–35g/day|Full high-fiber diet, nuts, seeds, raw vegetables| > 💡 **Tip:** If bloating or gas increases, slow down the fiber progression. Your bowel may need more time to adjust. ### Hydration Is Essential Fiber only works when paired with adequate fluid. As you increase fiber: - Drink at least **8–10 cups (64–80 oz) of water** per day - More if you are physically active or live in a hot climate - Adequate hydration keeps fiber moving through the digestive system and prevents constipation --- ### Foods with the Highest Fiber Content |Food|Serving|Approx. Fiber| |---|---|---| |Black beans (cooked)|½ cup|7.5g| |Lentils (cooked)|½ cup|8g| |Raspberries|1 cup|8g| |Pears (with skin)|1 medium|5.5g| |Avocado|½ medium|5g| |Broccoli (cooked)|1 cup|5g| |Oatmeal (cooked)|1 cup|4g| |Almonds|1 oz (23 nuts)|3.5g| |Whole wheat bread|1 slice|2g| |Apple (with skin)|1 medium|4.4g| --- ### What About Nuts, Seeds, and Popcorn? **Old advice (now outdated):** Avoid all nuts, seeds, and popcorn. **Current evidence:** Multiple large studies — including a 2025 prospective study of nearly 30,000 women — found that **eating nuts, seeds, and fresh fruits with seeds was NOT associated with increased risk of diverticulitis**.[^8] The earlier restriction was based on theoretical concerns, not clinical evidence. These foods are excellent sources of fiber, healthy fats, and antioxidants and are now encouraged as part of a healthy long-term diet. --- ## Part 3: Long-Term Prevention of Future Episodes About **20% of people** who have one episode of diverticulitis will have at least one recurrence.[^9] The good news: research shows that a **combination of healthy lifestyle behaviors can reduce your risk by up to 50%**.[^10] A landmark 2025 study following over 179,000 people across four prospective cohorts found that compared to individuals with no healthy lifestyle factors, those who maintained **all five key healthy habits** had a **50% lower risk of developing diverticulitis** — and this protective effect held true even in people with high genetic risk.[^11] ### The Five Most Important Preventive Lifestyle Factors --- ### 🥦 1. Adopt a High-Fiber, Anti-Inflammatory Diet **Target: 25–35 grams of dietary fiber per day** A meta-analysis of five large prospective cohort studies involving over **865,000 people** found that every 10 grams/day increase in dietary fiber was associated with a **26% reduction in diverticular disease risk**. People eating 30 grams of fiber per day had a **41% lower risk** compared to those eating 7.5 grams/day.[^12] The strongest protection comes from **fruit fiber and cereal/grain fiber** specifically. The benefit from vegetable fiber alone was less clear.[^13] **Anti-inflammatory dietary patterns** also matter beyond fiber alone. A large prospective study found that men eating the most pro-inflammatory diets had a **31% higher risk** of diverticulitis, and higher blood levels of C-reactive protein (CRP) and interleukin-6 (IL-6) — key inflammation markers — were also associated with increased risk.[^14] **Key dietary strategies:** - Eat **5+ servings of fruits and vegetables daily** (aim for variety and color) - Choose **whole grain breads, pasta, rice, and cereals** over refined/white versions - Include **legumes (beans, lentils, chickpeas)** at least 3–4 times per week - Add a daily **handful of nuts or seeds** (walnuts, almonds, chia, flaxseed) - Cook with **olive oil** as your primary fat (anti-inflammatory omega-9s) - Eat **oily fish** (salmon, sardines, mackerel) at least twice a week (omega-3s) - Limit **red meat to less than 51g/day** (about 2 oz or less) > 💡 **The Mediterranean Diet Pattern** — rich in plants, olive oil, whole grains, fish, and legumes — aligns closely with these recommendations and is associated with reduced gut inflammation, a more diverse microbiome, and reduced risk of colon disease.[^15] [^16] --- ### 🥩 2. Limit Red Meat, Processed Meats & Western-Diet Foods Red meat consumption is an independent risk factor for diverticulitis. A large prospective study of 46,295 men found that those eating the most Western-style diets (high in red meat, refined grains, and high-fat dairy) had a **55% increased risk** of diverticulitis compared to those eating the least. Conversely, men following a "prudent" dietary pattern (high in fruits, vegetables, whole grains) had a **26% reduced risk**.[^17] **Reduce or avoid:** - Processed meats (hot dogs, sausage, bacon, lunch meats, deli meats) - Red meat consumed daily (beef, pork, lamb) - Fried foods and fast food - Ultra-processed snack foods, packaged sweets, chips - Refined grains (white bread, pastries, sugary cereals) - High-fat dairy products consumed in excess --- ### 🏃 3. Exercise Regularly Physical activity is strongly and independently associated with lower diverticulitis risk. A systematic meta-analysis found that people with **high physical activity had a 24% lower risk** of diverticular disease compared to those with low activity.[^18] Women exercising more than 30 minutes per day had a **42% lower risk** of hospitalization for diverticular disease compared to those exercising less.[^19] The protective mechanism appears to be that exercise: - Promotes healthy bowel motility and regularity - Reduces visceral (abdominal) fat, which is linked to inflammation - Lowers circulating inflammatory markers (CRP, IL-6) - Supports a healthy gut microbiome **Recommended:** - Aim for at least **150 minutes of moderate-intensity exercise per week** (brisk walking, cycling, swimming, yoga) — or 75 minutes of vigorous activity - Include **vigorous activity at least 2 hours/week** (the level studied in major research cohorts)[^10] - Break up prolonged sitting throughout the day - Even walking 20–30 minutes most days is beneficial - Resume light walking as soon as you feel able after a flare, but avoid strenuous exercise until fully recovered --- ### ⚖️ 4. Maintain a Healthy Body Weight **Obesity is a significant and independent risk factor** for diverticulitis and its complications. A meta-analysis found that for every 5-unit increase in BMI, the risk of diverticular disease increased by **28%** and the risk of complications by **20%**.[^18] Women who gained more than 20 kg (44 lbs) since age 18 had a **73% increased risk** of diverticulitis.[^20] Importantly, the risk increases **even within the normal BMI range** — this is not just a concern for those who are obese. Abdominal fat (waist circumference) appears particularly important — likely because visceral fat promotes systemic inflammation, which is a key driver of diverticulitis.[^21] **Practical steps:** - Work toward and maintain a **BMI of 18.5–24.9** when possible - Focus on reducing **waist circumference** (aiming for under 35 inches for women; under 40 inches for men) - Weight loss, even modest amounts (5–10% of body weight), can meaningfully reduce inflammatory markers - Combine dietary changes with regular physical activity for best results - If struggling with weight, ask your doctor for a referral to a registered dietitian or weight management program --- ### 🚭 5. Quit Smoking — and Limit Alcohol **Smoking** is an established, modifiable risk factor for diverticulitis: - A 2026 meta-analysis of 62 studies (566,903 patients) found smoking increased the risk of diverticulitis by **59%** and diverticular bleeding by **51%**.[^22] - Even **ex-smokers** had a 31% higher risk compared to never-smokers.[^22] - In women, smoking was associated with a 20% higher risk of diverticulitis; combined smoking and alcohol use raised that risk to 60%.[^23] **Alcohol** consumed at high levels (≥30g/day or about 2+ standard drinks daily) was associated with a **26% increased risk** in women.[^23] **What to do:** - Seek help quitting smoking — medications (varenicline, bupropion) and nicotine replacement therapy are effective - Ask your doctor about smoking cessation programs, apps, or hotlines (1-800-QUIT-NOW) - Limit alcohol to **no more than 1 drink/day for women** and **2/day for men** (if you drink at all) --- ### 💊 6. Avoid NSAIDs (as able) Non-steroidal anti-inflammatory drugs (NSAIDs) such as **ibuprofen (Advil/Motrin), naproxen (Aleve), and aspirin (in pain-relief doses)** are associated with increased risk of diverticulitis and complications.[^4] [^5] - Talk to your doctor about switching to **acetaminophen (Tylenol)** for general pain management - **Do not stop prescribed NSAIDs** (for arthritis, heart disease, etc.) without talking to your doctor first - Low-dose aspirin prescribed for heart disease prevention is generally considered acceptable — discuss your specific situation with your provider --- ### 💧 7. Stay Well Hydrated - Aim for **at least 64 oz (8 cups) of water per day**, more in hot weather or with exercise - Adequate hydration is essential for fiber to work properly — fiber absorbs water to soften stool - Staying hydrated prevents constipation, which increases pressure in the colon - Limit caffeinated beverages and alcohol, which can dehydrate you --- ### 🦠 8. Support Your Gut Microbiome Emerging research has found that people with diverticulitis have a **distinctly different gut microbiome** compared to those without — including lower levels of beneficial butyrate-producing bacteria and higher levels of pro-inflammatory bacteria like _Ruminococcus gnavus_.[^24] **Dietary strategies to support gut health:** - Eat a diverse range of plant foods — variety is key to microbiome diversity - Include **fermented foods**: yogurt, kefir, kimchi, sauerkraut, miso (introduce slowly if unfamiliar) - Eat **prebiotic-rich foods** that feed beneficial bacteria: garlic, onions, leeks, asparagus, bananas, oats, Jerusalem artichokes **Probiotics:** A few small clinical trials suggest probiotic supplements may help reduce recurrence, but current evidence is not strong enough to make a firm recommendation.[^4] Some probiotics are probably safe to try — talk to your doctor before starting any supplement, particularly if you have a compromised immune system. --- ## Important Follow-Up Care ### Colonoscopy After Diverticulitis Depending on your history and the severity of your episode, your doctor may recommend a **colonoscopy 6–8 weeks after your episode resolves**. This is to: - Rule out colon cancer (rare cases can mimic diverticulitis on CT scan) - Check the extent of diverticulosis - Make sure the inflammation has fully healed Whether you need one depends on your age, when you last had a colonoscopy, and how severe your episode was. Follow your doctor's specific recommendation. ### When to Call Your Doctor Contact your healthcare provider if you experience: - Fever above 100.4°F (38°C) that persists - Worsening or severe abdominal pain - Blood in your stool - Vomiting that prevents you from keeping fluids down - Symptoms that are not improving after 2–3 days of treatment - Nausea, chills, or feeling significantly worse --- ## Summary: Your Action Plan at a Glance ### During an Acute Flare - [ ] Follow a clear liquid diet for 1–2 days (if instructed), then low-fiber soft foods - [ ] Take acetaminophen for pain; avoid NSAIDs - [ ] Stay well hydrated (8+ cups of water/day) - [ ] Rest and limit physical activity - [ ] Take antibiotics **only if prescribed** by your doctor - [ ] Call your doctor if symptoms worsen or don't improve in 2–3 days ### Recovery Phase (Weeks 1–4) - [ ] Slowly reintroduce fiber as symptoms allow (add 5–15g at a time) - [ ] Return to a high-fiber diet (25–35g/day) over 3–4 weeks - [ ] Continue hydrating well - [ ] Resume light walking/activity as tolerated - [ ] Attend all scheduled follow-up appointments ### Long-Term Prevention - [ ] Eat 25–35g of dietary fiber daily (fruits, vegetables, whole grains, legumes) - [ ] Follow a Mediterranean-style or other anti-inflammatory diet - [ ] Limit red meat to less than 51g per day; avoid processed meats - [ ] Exercise vigorously at least 2 hours per week (or 150 min moderate-intensity) - [ ] Maintain a healthy BMI and reduce waist circumference - [ ] Quit smoking; limit alcohol to 1–2 drinks/day or less - [ ] Avoid NSAIDs when possible; use acetaminophen instead - [ ] Stay hydrated (64+ oz water/day) - [ ] Eat a variety of plant foods to support your gut microbiome --- ## Questions to Ask Your Doctor 1. Should I have a colonoscopy after this episode? When? 2. Was my case complicated or uncomplicated — and does that change my long-term risk? 3. Do I need antibiotics, and if so, for how long? 4. Can I take a fiber supplement, and which type do you recommend? 5. Should I see a registered dietitian for more personalized guidance? 6. Are any of my current medications (especially NSAIDs) increasing my risk? 7. What symptoms should prompt me to return to the emergency room? --- ## Glossary of Terms |Term|Definition| |---|---| |**Diverticula**|Small, balloon-like pouches that form in the wall of the colon| |**Diverticulosis**|The presence of diverticula without inflammation or symptoms| |**Diverticulitis**|Inflammation or infection of diverticula| |**Uncomplicated diverticulitis**|Inflammation without abscess, perforation, or fistula| |**Complicated diverticulitis**|Involves abscess, perforation, bowel obstruction, or fistula| |**Dietary fiber**|The indigestible part of plant foods that adds bulk to stool and feeds gut bacteria| |**NSAID**|Non-steroidal anti-inflammatory drug (e.g., ibuprofen, naproxen)| |**Microbiome**|The community of trillions of bacteria living in your digestive tract| --- ## Footnotes & References [^1]: Brown RF, et al. [Diverticulitis: A Review](https://consensus.app/papers/details/9ef23a98330255cdbaf64ce28c4aa966/). _JAMA._ 2025. Annual US incidence approximately 180 per 100,000 people; 200,000 annual hospital admissions; >$6.3 billion estimated annual healthcare expenditure. [^2]: Mayo Clinic. [Diverticulitis Diet](https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/diverticulitis-diet/art-20048499). Clear liquids recommended for severe flares; clear liquid diets should not extend beyond a few days due to risk of malnutrition. [^3]: Cleveland Clinic. [Diverticulitis and Diverticulosis Diet](https://health.clevelandclinic.org/what-foods-should-you-eat-and-avoid-on-a-diverticulitis-diet). Updated May 2024. Low-fiber diet (8–12g/day) during flare; high-fiber diet (25–35g/day) for prevention. [^4]: Mayo Clinic. [Diverticulitis: Diagnosis and Treatment](https://www.mayoclinic.org/diseases-conditions/diverticulitis/diagnosis-treatment/drc-20371764). Recommendations on NSAIDs, probiotics, and follow-up care. [^5]: Peery AF, et al. [AGA Clinical Practice Update on Medical Management of Colonic Diverticulitis: Expert Review](https://consensus.app/papers/details/030f089d27185875bf3955263890f074/). _Gastroenterology._ 2020. Antibiotic use selectively (not routinely) in uncomplicated diverticulitis; avoid NSAIDs to reduce recurrence risk. [^6]: Chabok A, et al. [Randomized clinical trial of antibiotics in acute uncomplicated diverticulitis](https://consensus.app/papers/details/fbc83460838c5e3ba02b972db6cfef8f/). _British Journal of Surgery._ 2012. (AVOD trial; n=623) Antibiotic treatment did not accelerate recovery, prevent complications, or prevent recurrence. [^7]: Daniels L, et al. [Randomized clinical trial of observational versus antibiotic treatment for a first episode of CT-proven uncomplicated acute diverticulitis](https://consensus.app/papers/details/7946fa0e90145f729c7a7a9a115920c9/). _British Journal of Surgery._ 2017. (DIABOLO trial; n=528) Observation without antibiotics did not prolong recovery and can be considered appropriate in uncomplicated cases. [^8]: Barlowe TS, et al. [Diet and Risk for Incident Diverticulitis in Women: A Prospective Cohort Study](https://consensus.app/papers/details/0c8744af3a91532a825f93aad0d08caf/). _Annals of Internal Medicine._ 2025. n=29,916 women; intake of peanuts, nuts, seeds, and fresh fruits with edible seeds was not associated with increased diverticulitis risk. Healthy diets (DASH, HEI, AHEI) were associated with 19–23% reduced risk. [^9]: Strate LL, et al. [Epidemiology, Pathophysiology, and Treatment of Diverticulitis](https://consensus.app/papers/details/8182c9f8901b5f61864c836863866807/). _Gastroenterology._ 2019. Approximately 20% of patients with incident diverticulitis experience at least one recurrence. [^10]: Liu P-H, et al. [Adherence to a Healthy Lifestyle is Associated With a Lower Risk of Diverticulitis among Men](https://consensus.app/papers/details/3a51aa6084c85d0ca3cc867f1ec96fb0/). _American Journal of Gastroenterology._ 2017. n=757,791 person-years; adherence to all 5 low-risk lifestyle factors (fiber, red meat, BMI, exercise, non-smoking) reduced diverticulitis incidence by 50%. [^11]: Ma W, et al. [Lifestyle factors, genetic susceptibility and risk of incident diverticulitis: an integrated analysis of four prospective cohort studies and electronic health records-linked biobank](https://consensus.app/papers/details/d5b93d41406859bfbcddc1e37550f091/). _Gut._ 2025. n=179,564 participants across NHS, NHSII, HPFS, SCCS cohorts. A healthy lifestyle score of 5 (vs 0) associated with HR 0.50 for diverticulitis. Protective effect of healthy lifestyle held across low, mid, and high genetic risk categories. [^12]: Aune D, et al. [Dietary fibre intake and the risk of diverticular disease: a systematic review and meta-analysis of prospective studies](https://consensus.app/papers/details/629a8f1bf7525df5b45152357ee47d03/). _European Journal of Nutrition._ 2019. Meta-analysis of 5 prospective cohorts, 19,282 cases, 865,829 participants. Every 10g/day fiber = 26% risk reduction (RR 0.74). 30g/day fiber associated with 41% reduced risk vs 7.5g/day. [^13]: Carabotti M, et al. [Role of Dietary Habits in the Prevention of Diverticular Disease Complications: A Systematic Review](https://consensus.app/papers/details/156194a645135c4989a9cfc7ad6c2945/). _Nutrients._ 2021. High fiber intake associated with decreased risk of diverticulitis; protective effect seen for fruit and cereal fiber specifically. [^14]: Ma W, et al. [Association Between Inflammatory Diets, Circulating Markers of Inflammation, and Risk of Diverticulitis](https://consensus.app/papers/details/53d94d47c6bc53639dab0782fa6c2a5d/). _Clinical Gastroenterology and Hepatology._ 2019. n=46,418 men, 28 years follow-up. Highest quintile of pro-inflammatory diet associated with 31% increased diverticulitis risk. Elevated CRP associated with 85% increased risk; elevated IL-6 with 104% increased risk. [^15]: Tursi A, et al. [Colonic diverticular disease](https://consensus.app/papers/details/862ab877dff1551090e97d9dacfd10e6/). _Nature Reviews Disease Primers._ 2020. Mediterranean diet and fiber-rich diets associated with improved microbiome diversity and reduced gut inflammation. [^16]: Tursi A, et al. [Revised version global guidelines on diverticular disease of the colon: the Fiesole Consensus report](https://consensus.app/papers/details/3298ed56b4175d54b6f261ea9d79bd6c/). _Gut._ 2025. International Delphi consensus of 32 experts from 14 countries: high dietary fiber intake is protective; smoking, obesity, NSAIDs, corticosteroids, and opioids increase risk. [^17]: Strate LL, et al. [Western Dietary Pattern Increases, and Prudent Dietary Pattern Decreases, Risk of Incident Diverticulitis in a Prospective Cohort Study](https://consensus.app/papers/details/f670c215c123501083167cf5246a43d1/). _Gastroenterology._ 2017. n=46,295 men, 894,468 person-years. Western diet (HR 1.55) vs prudent diet (HR 0.74) for incident diverticulitis. [^18]: Aune D, et al. [Body mass index and physical activity and the risk of diverticular disease: a systematic review and meta-analysis of prospective studies](https://consensus.app/papers/details/1ff9fe7cbd72538094ee02f8907c6690/). _European Journal of Nutrition._ 2017. Meta-analysis of 6 cohort studies (1.6 million participants): each 5-unit BMI increase = 28% higher diverticular disease risk. High vs. low physical activity = 24% lower risk. [^19]: Hjern F, et al. [Obesity, Physical Inactivity, and Colonic Diverticular Disease Requiring Hospitalization in Women: A Prospective Cohort Study](https://consensus.app/papers/details/8fb97e57a79051a892a069cf72b60254/). _American Journal of Gastroenterology._ 2012. n=36,592 women. Exercise ≤30 min/day increased risk of hospitalization by 42%. BMI ≥30 associated with 2-fold increased risk of complicated diverticulitis. [^20]: Ma W, et al. [Association Between Obesity and Weight Change and Risk of Diverticulitis in Women](https://consensus.app/papers/details/dbab431d5bdd55c7bf7eddf491893470/). _Gastroenterology._ 2018. n=46,079 women. Adult weight gain ≥20 kg associated with 73% increased diverticulitis risk. BMI ≥35 associated with HR 1.42. [^21]: Wu YL, et al. [The role of circulating metabolomics in linking metabolic dysfunction, inflammation, and risk of diverticulitis outcomes](https://consensus.app/papers/details/8768c7c36d7e5a51b352229f8bf21cd9/). _eBioMedicine._ 2025. Metabolomic signatures of metabolic dysfunction associated with 97% higher risk of incident diverticulitis and 80% higher risk of recurrence. [^22]: Chitneni E, et al. [Smoking and alcohol consumption as risk factors for colonic diverticulosis and its complications: Systematic review and meta-analysis](https://consensus.app/papers/details/b2fb018809305eada3579cef32cf49c4/). _Medicine._ 2026. 62 studies, 566,903 patients. Smoking OR 1.36 for diverticulosis; OR 1.59 for diverticulitis; OR 1.51 for diverticular bleeding. Ex-smokers also at increased risk (OR 1.31). [^23]: Gunby SA, et al. [Smoking and alcohol consumption and risk of incident diverticulitis in women](https://consensus.app/papers/details/291693f30cc95833bae013ad3ee8126b/). _Clinical Gastroenterology and Hepatology._ 2023. n=84,232 women. Current smoking HR 1.20; past smoking HR 1.20; alcohol ≥30g/day HR 1.26. Combined smoking + high alcohol HR 1.60. [^24]: Ma W, et al. [Gut microbiome composition and metabolic activity in women with diverticulitis](https://consensus.app/papers/details/e378f1a3126a5559960694168376246b/). _Nature Communications._ 2024. Shotgun metagenomic sequencing in 121 matched pairs. Diverticulitis cases showed enrichment of pro-inflammatory _Ruminococcus gnavus_ and depletion of butyrate-producing bacteria. Fiber-rich diet's protective effect was modulated by microbiome composition. --- _This handout was prepared using evidence from peer-reviewed medical literature through 2025–2026, including guidelines from the American Gastroenterological Association (AGA), the 2025 International Fiesole Consensus on Diverticular Disease, and multiple prospective cohort studies and meta-analyses. For questions about your specific condition, please consult your physician or a registered dietitian._ _Date of preparation: May 2026_