Diverticulosis is a common condition where small, bulging pouches (diverticula) form in the wall of the large intestine. While many people with diverticulosis have no symptoms, the condition becomes known as diverticulitis if these pouches become inflamed or infected. The right nutritional choices can play a vital role in both preventing flares and managing them when they occur.
High-Fiber Diet: The Best Choice for Long-Term Management
For daily management and long-term prevention of diverticulitis flares, healthcare professionals recommend a high-fiber diet. Fiber adds bulk to stool, which helps it move more easily through the colon, reducing pressure and promoting regularity. Most Americans consume only 10 to 15 grams of fiber a day, far short of the recommended daily intake of 25 to 38 grams, depending on age and gender.
Good sources of dietary fiber include:
- Fruits: Apples and pears (with skin on), berries, prunes, and figs.
- Vegetables: Broccoli, cauliflower, carrots, leafy greens like spinach and kale, and winter squash.
- Whole Grains: Oats, whole wheat bread and pasta, brown rice, quinoa, and barley.
- Legumes: Beans (kidney, black), lentils, and chickpeas.
- Nuts and Seeds: Despite older recommendations to avoid them, current research suggests nuts and seeds (e.g., almonds, sunflower seeds, chia seeds) are not linked to an increased risk of diverticulitis and are excellent fiber sources.
To avoid gas and bloating when increasing your fiber intake, do so gradually over several weeks. Crucially, as you increase fiber, you must also increase your fluid intake. Fiber needs water to work effectively and keep stool soft.
Diet During a Diverticulitis Flare-Up
During an active flare-up of diverticulitis, the dietary rules change dramatically. The goal is to give the inflamed colon a rest by reducing solid waste that must pass through it. Depending on the severity of symptoms, your doctor may recommend starting with a clear liquid diet.
Phase 1: Clear Liquid Diet
For a day or two, especially with severe pain or fever, a clear liquid diet is typically advised.
Clear liquids include:
- Water and ice chips
- Clear broths (chicken, beef, or vegetable)
- Pulp-free juices (apple, white grape, cranberry)
- Plain gelatin
- Clear sports drinks and popsicles
- Tea or coffee without cream or milk
Phase 2: Low-Fiber Diet
As symptoms begin to improve, you will transition to a low-fiber, soft-food diet. These foods are easy to digest and gentle on the inflamed bowel.
Examples of low-fiber foods:
- Grains: White bread, white rice, white pasta, and low-fiber cereals like cornflakes or puffed rice.
- Protein: Tender, cooked poultry, fish, eggs, tofu, and smooth nut butters.
- Fruits: Applesauce, canned or cooked fruits without skin or seeds, and ripe bananas.
- Vegetables: Cooked, peeled, and seedless vegetables such as carrots, potatoes (without skin), and zucchini.
- Dairy: Milk, cheese, and yogurt (without seeds or fruit pieces), if tolerated.
Transitioning Back to a High-Fiber Diet
Once symptoms have fully resolved (usually within a week or two), it is crucial to gradually reintroduce high-fiber foods. This helps prevent future episodes. Start with small increases, adding 5 to 15 grams of fiber per day, and continue to increase your fluid intake. A registered dietitian can provide personalized guidance during this transition.
Foods to Reconsider or Avoid
While nuts and seeds are no longer on the "avoid" list, other foods may contribute to inflammation or be difficult to digest, particularly during flares or for some individuals.
- Red and Processed Meats: Some research links high consumption of red meat to an increased risk of diverticulitis flares.
- Processed Foods: Fast food, sugary snacks, and refined grains found in the Western diet are often low in fiber and can contribute to digestive issues.
- Spicy and Fried Foods: These can sometimes irritate the digestive tract and may be best avoided during flare-ups.
- Alcohol and Caffeine: These can be problematic for some individuals and may irritate the gut, especially during an acute attack.
Diverticulosis vs. Diverticulitis Diet Comparison
| Feature | Diverticulosis (Prevention/Remission) | Diverticulitis (Flare-Up/Recovery) |
|---|---|---|
| Diet Type | High-Fiber | Initially Clear Liquid, then Low-Fiber |
| Goal | Promote regular bowel movements and reduce colon pressure | Rest the inflamed colon to allow healing |
| Grains | Whole grains: oats, brown rice, whole wheat bread | Refined grains: white bread, white rice, pasta |
| Fruits | Fresh fruits with skins (e.g., apples, pears), berries | Canned fruits (no skin/seeds), applesauce, ripe bananas |
| Vegetables | Raw and cooked vegetables, skin and seeds included | Cooked, peeled vegetables (e.g., carrots, potatoes) |
| Nuts & Seeds | Allowed and encouraged as fiber source | Okay for long-term but often restricted during flare-ups. Can use smooth nut butters |
| Legumes | Beans, lentils, chickpeas | Avoid during flares; reintroduce slowly |
| Fluids | Plenty of water to aid fiber digestion | Start with clear liquids; stay hydrated throughout |
Conclusion
Dietary management for diverticulosis is a two-part process. A high-fiber diet rich in whole grains, fruits, vegetables, nuts, and seeds is the best approach for long-term prevention. However, during an acute diverticulitis flare-up, a temporary clear liquid and low-fiber diet is necessary to give the colon a chance to heal. Consulting with a healthcare professional or a registered dietitian is recommended to create a personalized nutrition plan, especially for managing symptoms and transitioning between dietary phases. Adopting a holistic approach that includes adequate hydration and regular physical activity can also significantly improve gut health. For more information, you can read about foods for diverticulosis and diverticulitis on the Johns Hopkins Medicine website.
