Diet for Diverticulitis: What to Eat in and After a Flare

Quick answer

Clear liquids, then low fibre, then high fibre when recovered

During an acute flare, doctors may recommend a clear-liquid diet for a few days, then a gradual return to low-fibre foods (white bread, white rice, eggs, fish, cooked peeled vegetables, canned fruit) as symptoms settle. Once you have recovered, a high-fibre diet (25–35 g a day) rich in fruit, vegetables, legumes and whole grains, with plenty of fluids and regular exercise, is advised to prevent recurrence. Current evidence does not support avoiding nuts, seeds and popcorn. Red and processed meat, obesity, smoking and inactivity increase risk. Mild uncomplicated diverticulitis is sometimes managed without antibiotics, but severe pain, fever, vomiting or blood need prompt care.

Important. Severe or worsening abdominal pain, especially in the lower left side, with fever, vomiting, inability to keep fluids down, a rigid abdomen, rectal bleeding or confusion needs urgent assessment, because complications (abscess, perforation, bleeding) can be serious.

What are diverticulosis and diverticulitis?

Diverticula are small pouches that bulge outwards from the wall of the colon, most often in the sigmoid colon on the lower left side. They are very common after age 50 and usually cause no symptoms (diverticulosis). When one becomes inflamed or infected, it causes diverticulitis, with abdominal pain (often lower left), fever, nausea and changes in bowel habit. About 4–15% of people with diverticulosis develop diverticulitis.

During a flare: clear liquids

For severe symptoms, a short period (1–3 days) of clear liquids rests the bowel: water, clear broth, pulp-free juice (apple, white grape), tea without milk, gelatin and popsicles without pieces.
Many people with mild diverticulitis can eat a low-fibre diet from the start, and clinicians increasingly allow this if tolerated.
Stay hydrated; seek care if you cannot keep fluids down.
Take prescribed medicines (antibiotics if needed) and pain relief as directed; paracetamol is preferred, and anti-inflammatories and opioids may be discouraged.
Follow your own clinician’s instructions, as management depends on severity.

Recovering: low-fibre foods

Grains: white bread, white rice, plain pasta, refined cereals such as cornflakes.
Protein: eggs, fish, skinless chicken, tofu, smooth nut butter.
Dairy: milk, yoghurt, cheese if tolerated.
Vegetables: well-cooked, peeled and seedless (carrots, squash, potatoes without skin, asparagus tips).
Fruit: applesauce, canned peaches or pears, ripe banana, melon.
Fats and others: butter, oils in moderation, broth, gelatin.
Continue for several days to a couple of weeks, then reintroduce fibre gradually.

After recovery: a high-fibre diet

Once symptoms have resolved (usually after 6 weeks, or as advised), gradually increase fibre to about 25–35 g a day. A high-fibre diet is associated with lower risk of diverticulitis and may reduce recurrence. Add fibre slowly over weeks and drink plenty of fluids to avoid bloating.

Fruit and vegetables: berries, pears, apples with skin, broccoli, leafy greens, peas, carrots.
Legumes: beans, lentils, chickpeas.
Whole grains: oats, barley, whole-wheat bread and pasta, brown rice, quinoa.
Nuts, seeds and popcorn in normal amounts (see below).

See foods high in fibre.

The nuts, seeds and popcorn myth

For decades, people with diverticular disease were told to avoid nuts, seeds, corn and popcorn because they might lodge in diverticula. Large studies have not found that these foods cause diverticulitis; in fact, nut and popcorn consumption was associated with a lower risk. Current guidelines do not recommend avoiding them. If you notice that a food triggers symptoms in you personally, you can limit it.

Habits that influence risk

Low-fibre diet, high intake of red and processed meat and refined grains increase risk.
Obesity, particularly abdominal fat.
Smoking.
Physical inactivity (regular vigorous exercise lowers risk).
Regular use of NSAIDs (ibuprofen, aspirin) and opioids.
Alcohol in excess.
Healthy weight, exercise and a plant-rich diet are protective.

Sample menus

Recovery phase (low fibre): scrambled eggs and white toast; chicken broth with white rice; baked fish with mashed potatoes and cooked carrots; applesauce and yoghurt.
Prevention phase (high fibre): oatmeal with berries and walnuts; lentil and vegetable soup with whole-grain bread; grilled salmon with brown rice and broccoli; fruit and nuts as snacks.
Drink water throughout the day.

Probiotics, supplements and medicines

Evidence for probiotics, mesalazine and rifaximin in preventing recurrence is limited or mixed. Fibre supplements (psyllium) can help if diet is not enough. Avoid regular NSAIDs if possible and discuss pain relief with your doctor. After repeated or complicated attacks, surgery to remove the diseased section of colon may be considered.

When to see a doctor

Lower abdominal pain with fever, nausea or change in bowel habit.
Severe or worsening pain, vomiting or inability to keep fluids down (urgent).
Rectal bleeding, which can be brisk and painless in diverticular bleeding.
No improvement after 2–3 days of treatment.
Repeated attacks, or complications in the past.
A colonoscopy 6–8 weeks after a first attack, if advised, to exclude other conditions.

Three common situations

First attack with mild pain: follow your doctor’s advice; a low-fibre diet and fluids, then gradual fibre.

Repeated bloating and left-sided cramps without fever: may be diverticular disease or IBS; discuss with your doctor.

Rectal bleeding: seek medical attention promptly.

How to increase fibre without discomfort

Raise your fibre intake by about 5 g every week or two, rather than all at once, and drink at least 1.5–2 litres of fluid a day. Start with soft sources such as oats, ripe fruit, cooked vegetables and well-cooked lentils, then add whole grains and raw vegetables. Gas and mild bloating usually settle after a couple of weeks. Psyllium husk, one teaspoon in a large glass of water, is a gentle option if food alone is not enough. If you develop pain or fever when adding fibre, stop and contact your doctor.

Long-term habits that lower the risk of recurrence

Eat plenty of fruit, vegetables, legumes and whole grains every day.
Limit red and processed meat.
Exercise regularly, at least 150 minutes a week of moderate activity.
Maintain a healthy weight.
Do not smoke.
Avoid regular use of NSAIDs unless prescribed, and tell your doctor if you take opioids.
Seek early advice for any new left-sided abdominal pain with fever.

Key points to remember

Diet follows the stage: clear liquids or low-fibre foods during a flare, then a high-fibre, plant-rich diet with exercise to reduce recurrence. Nuts and seeds are not forbidden. Seek urgent care for severe pain, fever or bleeding. Our nutrition team can help you plan the transition.

This guide is for general information and does not replace an assessment by your own doctor or dietitian.

Questions about diet for diverticulitis

These answers are general information and do not replace an examination or individual medical advice.

What should I eat during a diverticulitis flare?

Clear liquids for a few days if severe, then low-fibre foods, as your doctor advises.

When can I eat fibre again?

Gradually after symptoms settle, and once recovered aim for 25–35 g a day.

Do I need to avoid nuts and seeds?

No. Studies do not support avoiding them.

Does a high-fibre diet prevent diverticulitis?

It is associated with lower risk and is recommended after recovery.

Are probiotics helpful?

Evidence is limited; they are not routinely recommended.

When is diverticulitis an emergency?

With severe pain, fever, vomiting, a rigid abdomen or heavy bleeding.

Sources

This guide is for general information and does not replace medical advice. How a problem is diagnosed and treated depends on your examination and medical history. If you think you have an emergency, contact your local emergency services.