When you’re not experiencing a flare, eating a variety of foods, including fiber, can promote gut health and reduce flares. However, switching to easier-to-digest foods during a flare may help relieve symptoms.

Some people may find that avoiding certain foods helps diverticulitis symptoms, particularly during a flare-up.

FODMAPs are types of carbohydrate. The acronym stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols.

Some research suggests that a low FODMAP diet could prevent high pressure in the colon, which, in theory, could help people avoid or correct diverticulitis.

Following a low FODMAP diet may help some people with diverticulitis. This diet is sometimes used by people with irritable bowel syndrome (IBS) to reduce bloating and cramping.

High FODMAP foods include:

  • certain fruits, such as apples, pears, and plums
  • dairy foods, such as milk, yogurt, and ice cream
  • fermented foods, such as sauerkraut or kimchi
  • beans
  • legumes
  • foods high in trans fats
  • soy
  • cabbage
  • Brussels sprouts
  • onions and garlic

You may want to try reducing these and other high FODMAP foods to see if your symptoms improve. However, this diet is not recommended long term as it risks nutritional deficiences.

When following a low FODMAP diet plan, it’s important you still get enough nutrition from other foods. Working with a dietitian can help you get the balance right.

The relationship between fiber and diverticulitis is complex.

Since fiber can soften your body’s waste material, softer stool passes through your intestines and colon more quickly and easily. This reduces the pressure in your digestive system, which helps prevent the formation of diverticula. Adults are generally recommended to get 25 to 30 g of fiber in their diet per day.

However, if you’re having an acute attack of diverticulitis, your doctor may suggest either a low fiber diet or a clear liquid diet temporarily to help relieve your symptoms and reduce the increased colon contractions that fiber can cause.

Once symptoms improve, they may recommend sticking with a low fiber diet until symptoms disappear, then building up to a high fiber diet to prevent future flares.

Low fiber foods

Low fiber foods to consider eating if you have symptoms of diverticulitis include:

  • white rice, white bread, or white pasta (but avoid foods that contain gluten if you’re intolerant)
  • dry, low fiber cereals
  • processed fruits, such as applesauce or canned peaches
  • cooked animal proteins, such as fish, poultry, or eggs
  • olive oil or other oils
  • yellow squash, zucchini, or pumpkin without skin or seeds
  • cooked spinach, beets, carrots, or asparagus
  • potatoes with no skin
  • fruit and vegetable juices

Clear liquid diet

A clear liquid diet is a more restrictive approach to relieving diverticulitis symptoms. Your doctor may suggest it for a short period of time.

A clear liquid diet usually consists of:

  • water
  • ice chips
  • soup broth or stock
  • gelatin, such as Jell-O
  • tea or coffee without any creams, flavors, or sweeteners
  • clear electrolyte drinks

High fiber foods

A diet high in fruits, vegetables, and whole grains may decrease the risk of developing diverticulitis. However, it’s best to increase your fiber intake slowly so you do not cause digestive symptoms as your body adjusts.

  • beans and legumes, such as navy beans, chickpeas, lentils, and kidney beans
  • whole grains, such as brown rice, quinoa, oats, amaranth, spelt, and bulgur
  • vegetables
  • fruits

When adding fiber to your diet, be sure to drink plenty of water to avoid constipation.

However, remember each person is different. It’s always a good idea to consult a medical professional before making large dietary changes. Working with a gastroenterologist and dietitian can help you safely incorporate fiber into your diet.

The standard Western diet is often high in fat and sugar and low in fiber, which may increase your risk of developing diverticulitis.

A 2017 study involving more than 46,000 male participants suggests that avoiding the following foods may help prevent diverticulitis or reduce its symptoms:

  • red meat
  • refined grains
  • full fat dairy
  • fried food

Eating a diet high in red and processed meats could increase your risk of developing diverticulitis. Red meat is linked to inflammation in certain organs, and it’s best to avoid excessive consumption to prevent health issues.

Eating poultry or fish instead could be a healthier alternative to red meat.

In general, if you have diverticulosis but you’re not having an episode of diverticulitis, a diet high in fiber can help prevent future flare-ups.

Depending on the severity of an acute diverticulitis flare-up, a diet low in fiber or a clear liquid diet may be beneficial to reduce symptoms.

If you have diverticulitis, talk with your doctor about your food needs and food restrictions. It’s important to discuss how food may help or worsen your condition and make sure you make any dietary changes safely.

In addition, stay in communication with your doctor about your condition. While diverticulitis may remain in remission for long periods of time, keep in mind that it’s a chronic condition.