How Can Diverticulosis Be Prevented?

Nobody can guarantee the prevention of diverticulosis, and no clinical trial has shown that any diet, supplement or medicine stops pouches forming in the colon. NICE screened 6,070 research records for its 2019 evidence review on preventing diverticular disease in people with diverticulosis and included none. Age and genes drive much of the risk, and nobody can change either. Large observational studies link higher fibre intake, regular physical activity and a healthy body weight with a lower risk of diverticulitis, but these studies show associations and not proof. This article separates what research has established from what our members report, so that you can have a better-informed conversation with your own doctor.

What Does Preventing Diverticulosis Actually Mean?

The phrase covers three separate questions, and the evidence differs for each. Diverticulosis means small pouches (diverticula) in the colon wall, usually with no symptoms. When pouches cause ongoing lower tummy pain or bowel changes without infection, doctors call it diverticular disease. When a pouch becomes inflamed or infected, the condition is diverticulitis. Our guide to the difference between diverticulosis and diverticulitis explains the terms in full.

Diverticulosis is common and usually silent. The NICE evidence review reports that up to 40% of people aged 65 to 69 may have it, and that 55% of those had no abdominal pain in the previous three months. Kruse and Leifeld, authors of a review on prevention, estimate that about one in three people with diverticulosis eventually develop symptoms and that about 5% develop complications such as an abscess or perforation. NICE writes that many people with diverticulosis, perhaps the majority, never develop diverticular disease. Estimates differ because researchers define the stages in different ways.

This article covers those three questions. It does not cover recovery from a flare, which our treatment pages explain.

Why Do Members Feel So Confused About Prevention?

Members describe prevention advice as the most contradictory part of living with the condition. In one Facebook discussion that drew well over a hundred comments, members reported hearing that they should eat more fibre, that fibre made things worse, that nuts and seeds were dangerous, that nuts and seeds were fine, and that every bite needed chewing for 20 seconds, 30 chews or 32 chews. Nobody in the thread could point to research behind any of those numbers. Many members said their doctors gave them a single sentence of advice and nothing more.

“Of course I asked my doctor. He says to eat high fibre, take psyllium and not get constipated. Ok. Done. But it still baffles me, which is why I’m asking on this support group. I thought that is what we are here for.”

Dorothy, Hobart

Other members described leaving hospital with no guidance at all after a first flare.

“They put me straight on antibiotics for three days. Then let me leave with no information on how to manage it.”

Rosemary, Leicester

Doctors sometimes give members opposite advice about foods. One member said no doctor ever told her to avoid any food.

“I wasn’t told to avoid any foods, and I eat nuts and seeds. I had four flares in three and a half years and had a partial colectomy two years ago.”

Vivienne, Bath

The same discussion contained a reminder that a Facebook thread cannot replace a clinician.

“If you are concerned about something serious, ask a doctor, not Facebook. That will definitely send you in circles.”

Eileen, Aberdeen

Both views have merit. A group cannot diagnose anyone, but members also say they learned things in the group that their appointments did not cover. The confusion has a documented cause, which the next section sets out.

What Did NICE Find About Preventing Diverticular Disease?

NICE found no trial evidence on preventing diverticular disease in people with diverticulosis. The NICE evidence review (November 2019), also available as an NCBI Bookshelf copy, searched for randomised trials and, where none existed, for observational studies. It screened 6,070 records, assessed 17 in full and included none. The review lists the best-known fibre studies among its exclusions, including the 2012 Peery colonoscopy study and the 2008 nuts and popcorn study, because they examined a different condition or population from the one the review defined.

With no evidence to rate, the committee ran a Delphi exercise. A Delphi panel is a structured consensus process in which experts vote on statements over several rounds. The panel recommended dietary and lifestyle advice and consideration of bulk-forming laxatives. The table shows what happened to each statement.

The committee also wrote that the usual advice for people with diverticulosis, a high-fibre diet plus less alcohol, stopping smoking and exercise, rests on general health knowledge and not on evidence in people with diverticulosis. It called for research on which factors make diverticulosis progress to diverticular disease, and for trials of fibre supplements, vegetarian diets against diets that include meat, and soluble against insoluble fibre.

This explains much of what members report. Doctors still give prevention advice, but the advice rests on expert opinion, observational studies and general health principles, so it varies from clinician to clinician.

Does A High Fibre Diet Prevent Diverticulosis?

The best-known test of this question found no link between fibre and pouches. Dr Anne Peery and colleagues compared 539 people who had diverticulosis at colonoscopy with more than 1,500 people who did not. Their 2012 study found no association between constipation and pouches. People with fewer than seven bowel movements a week had lower odds of diverticulosis, not higher. Straining and incomplete emptying showed no association, and fibre intake showed none either (odds ratio 0.96 comparing the highest and lowest quarters of intake).

Two limits apply. The study captured one moment in time, and it examined asymptomatic diverticulosis, not diverticulitis. Other research points the other way for inflammation. A British cohort study of 47,033 men and women, reported by Kruse and Leifeld, found that 3.0% of vegetarians and 4.4% of non-vegetarians were admitted to hospital with diverticular disease, and that people eating 25.5 g of fibre a day had a 41% lower risk than people eating under 14 g.

The sources therefore disagree, and the table shows how.

Members split into the same camps as the research. Some believe fibre protects, some report that fibre makes them worse, and some report that neither fibre nor bowel habit explained their diagnosis.

“When newly diagnosed people look for advice, they are often told to avoid so many foods and take numerous supplements when, the chances are that with a simple high fibre diet they may never develop diverticulitis!”

Joyce, Cheltenham

“Fibre is a broad term and not all fibres are alike. Some that carry a health halo, like inulin, can be harmful. As the old saying goes, one man’s meat is another man’s poison.”

Gordon, Harrogate

Joyce’s view matches the NHS and the cohort studies, and no trial has confirmed it. Gordon’s point about different fibre types matches the NICE call for research on soluble against insoluble fibre. Both members describe what they experienced, and neither account settles the question for anyone else.

Can You Have Constipation Without Knowing?

Several members questioned whether “regular” means what people think. One described constipation alongside loose stools, and another discovered it on a scan.

“You can have diarrhoea and be constipated. Most people don’t know this. I always thought I was “regular” but in reality I was constipated, and adding fibre with plenty of water has helped my situation.”

Lorraine, Perth

“I thought I was regular and didn’t have pains or problems going. I went twice a day most days, but the CT showed otherwise.”

Barbara, Dunedin

Other members reported the opposite pattern.

“I have IBS so I go every day and I’m never constipated, and I was diagnosed with diverticulitis in January. I don’t think it matters if you’re constipated or not.”

Natalie, Manchester

“I had an abscess on my second flare-up, and I was going regularly.”

Trevor, Swansea

The Peery study supports the second group for pouch formation, since constipation did not predict pouches. The NICE panel kept fibre advice for people with constipation, which supports the first group for symptom control. The two findings can both hold, because pouch formation and symptoms are different stages.

Do Body Weight And Physical Activity Change The Risk?

Observational studies link higher body weight and lower activity with more hospital admissions for diverticulitis. The NICE committee noted large observational evidence that vigorous exercise associates with lower risk of acute diverticulitis and that a higher body mass index associates with symptomatic disease. Kruse and Leifeld report the following figures from two Swedish studies.

These are associations. People who weigh less and move more also differ in many other ways, and no trial has tested whether changing weight or activity prevents diverticulosis. Our article on exercise and diverticulitis covers what members report about running, walking and flares. The discussion behind this article showed that a healthy routine does not guarantee protection.

“My diet has always been healthy and I walk my dog most days, so being diagnosed was a big surprise.”

Rhona, Inverness

Does Cutting Red Meat Prevent Diverticulosis?

The evidence does not yet say. The NICE panel removed the statement on reducing red meat because respondents found no evidence for it, and the committee listed red meat as a research question. The German guidance summarised by Kruse and Leifeld recommends a low-meat diet, and British vegetarians had fewer admissions in the cohort study above. Members gave different reasons for cutting red meat, and most reasons concerned digestion and not prevention.

“I quit red meat because I couldn’t chew it up enough. Solved many flare-ups, I’m sure.”

Beryl, Exeter

Does Chewing Food Thoroughly Prevent Flares?

No study reviewed for this article tests chewing, yet it was the most popular prevention strategy in the discussion. Members who chew carefully often report fewer flares, and members who chew carefully and still had flares or surgery also posted. Our causes page covers the debate about whether food or stool lodges in a pouch in the section on what gets stuck in the pouches, and this article covers only the prevention claim.

“I did not chew my food enough. Since I now chew everything almost to mush, I do not get a flare. Chewing well is part of the way I handle this disease. Does anyone remember being told years ago to chew everything 30 times before swallowing? Back then I thought that was ridiculous.”

Pamela, Worcester

“I have improved my chewing since my diagnosis and do see some improvement. But some seeds, nuts, popcorn and pips are impossible, in my opinion, to chew to a very smooth paste. So I do avoid them personally.”

Linda, Salisbury

A third member reported that chewing worked for a time and then stopped working.

“I tried that and it worked for a while, until I was hospitalised twice in two months. That’s when I made the decision to have the surgery. Not all home remedies work long term, and they can put you at risk of emergency surgery. Just my experience and thoughts. Do what works for you.”

Sheila, Brisbane

Another member disagreed that chewing is a “home remedy” and argued that surgery treats the damaged section and not the habits behind it. The group did not resolve this, and the research cannot resolve it either. The NHS advises contacting a GP as soon as possible if you have symptoms of diverticular disease or diverticulitis, whatever you chew.

Do Fluids, Psyllium And Laxatives Help?

NICE’s panel reached consensus that bulk-forming laxatives deserve consideration for people with diverticulosis, but NICE could not judge their cost-effectiveness in this group because no trials exist. The committee noted that bulk-forming laxatives help soften stool and can also firm up loose stools. It costed them at February 2018 NHS Drug Tariff prices of about £3 to £14 a month, depending on the product. Psyllium husk (ispaghula) is one bulk-forming product, and our article on Fybogel and diverticulitis covers members’ experiences with it.

Members report mixed results with psyllium.

“My father took psyllium husk every night, two heaped spoons, and went every morning. He had no flare-ups doing this for over 20 years until his death.”

Frances, Chester

“Psyllium definitely binds me up.”

Kathleen, Leeds

The NICE panel reworded its statement on fluids so that it applies when a person increases fibre, and the NHS says gradual increases with plenty of fluids limit bloating. Members echoed this link between fibre and water. Our guide to the best drinks for diverticulitis covers hydration in more detail.

“I’m much better when I drink lots of water.”

Janet, Torquay

Do Toilet Habits And Access To A Toilet Play A Part?

Some members link their diagnosis to years of ignoring the urge to go. No study reviewed for this article tests that idea. Members described jobs without toilet access and households where the toilet was not free when the urge arrived.

“I have never been constipated, but I worked in a job where I couldn’t get to the toilet when I needed to, and I think this is what caused my diverticulitis.”

Hilary, Nottingham

“I live in a household with only one toilet. Most mornings I really want to go but have to wait, and by the time the toilet is free I have lost the urge. Apparently this trains the bowel to not let go, and then I find it hard to empty satisfactorily.”

Hazel, Stirling

A researcher who wrote a 2021 reader’s letter to the BMJ proposed that the seated Western toilet posture contributes to diverticula. The writer disclosed that his website once sold a squatting device. A reader’s letter is not a clinical study, and nobody has tested the idea in trials. The letter also cites a 2021 editorial by Dr Peery titled “Bowel Movement Frequency Linked to Increased Diverticulitis Risk in 2 Prospective Cohort Studies”. The writer’s reading of that editorial is his own, and this article reports only its title.

Can Medicines Or Supplements Prevent Diverticulosis From Progressing?

Researchers have tested several medicines, but mostly in people who already have symptoms or who have recovered from a flare, not in people whose pouches were found by chance. Treat the table as research findings and not as options to try. Prescription medicines need a doctor’s decision. Kruse and Leifeld also report that two large placebo-controlled trials of prevention in recurring diverticular disease (PREVENT 1 and PREVENT 2) produced disappointing preliminary results.

Members swap many supplement suggestions in the group. This article does not cover them, because no trial has tested most of them and our no-recommendation approach means we report evidence and not products.

Does Stress Play A Part In Prevention?

Many members believe stress shaped their diagnosis or their flares, and none of the research reviewed here tested stress management as prevention. Members described anxiety that they did not notice until the pain started.

“We talk about food being a problem. But emotions are a big problem. I’m anxious and I don’t even realise it. A little more anxiety and a flare gets started.”

Elaine, Wollongong

Our article on stress and diverticulitis symptoms covers the gut and brain link in depth. For what members say sets off a flare once the condition exists, read What Triggers Diverticulitis Flare Ups? and Does Food Trigger Diverticulitis?.

Which Questions Can You Take To Your Doctor?

Members said they wished they had arrived at appointments with questions. These questions follow from the evidence above, and your own clinician can answer them for your situation.

• • Where in my colon are the pouches, and what did the test show?
  • Do I have diverticulosis alone, or do my symptoms suggest diverticular disease?
  • Does my bowel pattern, including any constipation I may not have noticed, change what fibre advice suits me?
  • Do any of my current medicines affect my risk? Our causes article lists the medicine links that large studies report.
  • Which symptoms should make me contact you or seek urgent help?
  • Would a referral to a registered dietitian help me?
  • What follow-up, if any, applies to me?

How Does This Article Differ From Our Other Pages?

Each of our articles answers a different question. Use this table to find the one that matches yours.

For an overview of every stage, read our ultimate guide to diverticulosis and diverticulitis.

Frequently Asked Questions

Does Everyone With Diverticulosis Develop Diverticulitis?

No. NICE writes that many people with diverticulosis, perhaps most, never develop diverticular disease. Kruse and Leifeld estimate that about one in three eventually develop symptoms and about 5% develop complications. Nobody can yet predict who will progress, which is why NICE asked for research on that question.

Can You Prevent Diverticulosis If It Runs In Your Family?

Nobody can guarantee it. Twin studies cited by Strate and Morris attribute 40% to 50% of the risk of diverticular disease to genetic factors. No source reviewed for this article shows that a lifestyle change cancels that inherited share, and our causes article covers the genetics in more detail.

Do Fibre Supplements Prevent Diverticulosis?

No trial has shown this. NICE’s panel agreed that bulk-forming laxatives deserve consideration, and NICE listed fibre supplementation as a research question. Ask your GP or pharmacist whether a fibre product suits your bowel pattern and your other medicines.

Does Drinking More Water Prevent Diverticulosis?

No study reviewed tests water alone. NICE’s panel applied its fluid statement to people who are increasing their fibre, and the NHS says plenty of fluids help limit the bloating that a fibre increase can cause.

Does A Vegetarian Diet Lower The Risk?

Observational data suggest it may. A British cohort study reported hospital admissions with diverticular disease in 3.0% of vegetarians and 4.4% of non-vegetarians. NICE lists vegetarian diets as a research question, so the effect on people with diverticulosis remains untested in trials.

Do I Need Follow-Up After A Colonoscopy Finds Diverticulosis?

NICE’s panel agreed in its first round that routine follow-up has a place, but the evidence review does not describe a schedule. Ask your GP what follow-up applies to you. The NHS advises contacting a GP as soon as possible if you develop symptoms of diverticular disease or diverticulitis.

More Reading

Is Fybogel Safe To Take If You Have Diverticulitis?

“Left To Get On With It”: What Our Members Really Think About Medical Support After A Diverticulitis Diagnosis

What Foods Make Diverticulitis Worse?

Can Stress Trigger Diverticulitis Symptoms?

Does Food Trigger Diverticulitis? What Our Community’s Experience Reveals

Key Takeaways

• • No clinical trial shows that any diet, supplement or medicine prevents diverticulosis, and NICE included no studies in its 2019 prevention review.
  • NICE’s advice comes from a Delphi panel. The panel kept whole grains, fruit and vegetables, bulk-forming laxatives, weight loss, exercise and follow-up, and removed red meat reduction and the 30 g fibre target.
  • The Peery colonoscopy study found no link between fibre or constipation and pouch formation, while cohort studies link higher fibre intake with fewer hospital admissions for diverticular disease.
  • Observational studies link a higher body mass index and low physical activity with more hospital admissions for diverticulitis, but they show association and not proof.
  • Medicine trials, including rifaximin, mesalazine and probiotics, studied people with symptoms or recent diverticulitis and report limited or mixed results.
  • Members hear contradictory advice, so bring your own questions to your own doctor.

Sources

• • National Institute for Health and Care Excellence. Diverticular disease: diagnosis and management. Evidence review A: prevention of diverticular disease in patients with diverticulosis. NICE guideline NG147, November 2019.
  • National Guideline Centre (UK). Evidence review for prevention of diverticular disease in patients with diverticulosis. NCBI Bookshelf, NBK558079 (NCBI copy of the NICE review).
  • Kruse E, Leifeld L. Prevention and Conservative Therapy of Diverticular Disease. PubMed Central, PMC4789966.
  • Peery AF et al. A High-Fiber Diet Does Not Protect Against Asymptomatic Diverticulosis. Gastroenterology, 2012.
  • Strate LL, Morris AM. Epidemiology, Pathophysiology, and Treatment of Diverticulitis. Gastroenterology, 2019.
  • Diverticular disease and diverticulitis.
  • Isbit J. Prevention of diverticular disease. Rapid response to Management of colonic diverticulitis, BMJ 2021;372:n72.

Members who want to track their own patterns can start the Food And Symptoms Diary or join the conversation in our forums and our Facebook group. Reading what other members experience will not settle the science, but it shows you that you are not alone with the questions.

Disclaimer: This article does not constitute medical advice. Diverticulitis affects everyone differently. Always seek advice from a qualified medical practitioner about your own symptoms, diagnosis and treatment.