Is Diverticulitis Genetic? What Twin, Gene and Lifestyle Research Says About Family Risk

Is Diverticulitis Genetic? What Twin, Gene and Lifestyle Research Says About Family Risk

This article is for educational purposes only. It does not replace medical care, diagnosis, or genetic counseling (a session where a trained professional explains genetic risk and testing options). For any decision about testing, treatment, or care, consult a licensed physician, a medical geneticist, or an ABGC-certified genetic counselor. In emergencies, call 911.

Bottom line: Research shows that diverticular disease clusters in families. Danish and Swedish twin studies tie roughly 40% to 53% of the spread in risk to genes. Even so, diverticulitis stays uncommon. Fewer than 5 out of 100 people with colon pouches ever get it. A large 2025 study found that a healthy lifestyle was linked to lower risk at every level of genetic risk.

What you’ll learn

• What twin, sibling and gene-mapping studies really measured, and what their numbers mean for one person.
• How to turn a “more likely than average” gene report into a plain number out of 100.
• What current US guidelines and trials say about diet, antibiotics and surgery.
• What a family history means for siblings and children, and how US and Canadian gene privacy laws apply.

1. Diverticulosis vs. diverticulitis: what the condition is and why it is not one gene

Diverticula are small pouches that push outward through weak spots in the colon wall. They form mostly in the sigmoid colon, the S-shaped last part of the large bowel.

Having the pouches is called diverticulosis. Most people with pouches have no symptoms at all. Diverticulitis is the name for the moment those pouches become inflamed.

Think of an old garden hose with a few soft bulges. The bulges alone cause no trouble. A problem starts only if one of them gets sore or tears.

Pouches are very common with age. More than 30% of US adults aged 50 to 59 have them. More than 70% of people older than 80 have them.

Inflamed pouches are far less common, but they still fill hospital beds. About 200,000 people in the US are admitted to the hospital for a flare each year. About 71,000 more are admitted for bleeding from the pouches.

Term	What it means	How common
Diverticulosis	Pouches in the colon wall, usually without symptoms	Over 30 in 100 adults aged 50-59, and over 70 in 100 adults past 80
Diverticulitis	Inflamed pouches, often with pain and fever	Fewer than 5 in 100 people with diverticulosis
Complications	Abscess, fistula, blocked bowel, perforation, peritonitis	A minority of diverticulitis cases

Under age 50, flares are more common in men. From age 50 on, they are more common in women.

The common form of the condition is polygenic. That means many common gene variants each nudge risk up or down by a small amount. No single gene causes it.

This is very different from a single-gene condition, where one variant can carry a large risk. A polygenic risk score is a number that adds up many small-effect variants. It ranks a person’s genetic risk against other people.

Rare inherited disorders of connective tissue, the body’s support tissue, have also been tied to pouch disease. Examples include Ehlers-Danlos syndrome (which affects collagen) and Williams syndrome (which affects elastin). Polycystic kidney disease has also been linked. These rare conditions are a separate case from a common polygenic score.

If pouches showed up on a colonoscopy report, a primary care clinician can explain what that finding means for one person.

Section recap: Pouches in the colon are common after 50, while inflamed pouches are not. The common form is shaped by many small gene effects plus lifestyle, not by one gene.

2. What twin and gene-mapping research says about the genes involved

Researchers use different study designs to ask different questions. Each design gives a different kind of number. Mixing them up is the most common source of confusion.

Twin studies measure heritability

Heritability is the share of differences in risk across a group of people that is linked to gene differences. It is not a person’s chance of getting the disease.

A Danish nationwide study used health records covering 142,123 cases of diverticular disease, including 923 twins. It put heritability at 53%, with a 95% confidence interval of 45% to 61%.

A confidence interval is the range where the true value most likely sits. A narrow range means a more exact estimate.

The Danish twins also showed a sex gap. The twin link was stronger in female identical twins than in male identical twins (0.60 vs 0.33).

A Swedish study linked 104,452 twins to hospital records. Of these, 2,296 had pouch disease. It put heritability at 40%. The other 60% was linked to each person’s own life and surroundings.

The Swedish study also gave odds ratios. An odds ratio compares the odds of a condition between two groups. A value above 1 means higher odds in the first group.

If one identical twin had the disease, the co-twin’s odds ratio was 7.15 (95% CI 4.82-10.61). For same-sex fraternal twins, it was 3.20 (2.21-4.63). Identical twins share nearly all genes, so the bigger number points to a gene role.

Sibling data measure relative risk

Relative risk is how many times more likely an outcome is in one group than in another. A relative risk of 2 means twice as likely.

In the Danish data, siblings of people with the disease had a relative risk of 2.92 (95% CI 2.50-3.39). The group they were compared with was the general population. The extra risk was similar for brothers and sisters.

The sibling risk was strongest when the affected sibling had been in the hospital or had surgery. The study counted all pouch disease, not just flares. It gave no figure for the risk from a parent to a child.

Gene-mapping studies find many small effects

A genome-wide association study (GWAS) scans hundreds of thousands of gene markers across many people. It looks for spots in the genome that are more common in people with a condition.

An Icelandic whole-genome study with Danish follow-up first found variants near ARHGAP15, COLQ and FAM155A. Each variant changed the odds only a little, with odds ratios of about 0.82 to 1.23.

In 2018, a larger GWAS used 27,444 UK Biobank cases and 382,284 controls. It repeated its results in the Michigan Genomics Initiative. It found 42 loci (gene spots), 39 of them new, and it confirmed the three earlier genes.

The genes pointed to the build of the colon wall. They were active in the cells that make up the body’s support tissue. They had roles in how wall tissue holds together, how cells stick to each other, immunity, and how the bowel moves. The study also found shared gene causes with obesity and hernia.

A 2025 pooled study of past gene scans found 126 more gene spots. It is a preprint, not yet peer reviewed. It pointed to the colon’s smooth muscle and to interstitial cells of Cajal, the colon’s pacemaker cells. Tissue from surgery for severe flares showed less elastin in the sigmoid colon wall.

Study design	What it measures	Key number
Twin study, Denmark	Heritability	53% (95% CI 45%-61%)
Twin study, Sweden	Heritability	40%
Sibling cohort, Denmark	Relative risk for siblings	2.92 (95% CI 2.50-3.39)
GWAS, Iceland and UK	Small effects at many gene spots	Odds ratios about 0.82-1.23 per variant
GWAS meta-analysis, 2025 preprint	More gene spots	126 new loci, not peer reviewed

A doctor or genetic counselor can help sort out which of these numbers, if any, fits a specific family.

Section recap: Twin studies give heritability, sibling data give relative risk, and gene-mapping studies find many tiny effects. The genes mostly point to colon-wall strength and how the bowel moves.

3. Translating “higher than average” into absolute risk

Relative risk says “how many times more.” Absolute risk says “how many out of 100.” Only absolute risk shows the real size of a worry.

Picture a raffle with 100 tickets and 4 winners. Doubling the odds sounds big. It still means most tickets do not win.

Start from the baseline

The NIDDK states that fewer than 5 out of 100 people with diverticulosis develop diverticulitis. The 2026 ACG guideline puts the lifetime risk of diverticulitis at 3% to 5%.

A VA study followed 2,222 people whose pouches were found during colonoscopy. Over an 11-year follow-up period, 4.3% had a flare. That is about 4 out of 100 people.

Only 1% met a strict definition confirmed by imaging or surgery. The median time to a first flare was 7.1 years. The ACG guideline sums up this study as about 1% to 4% over 7 years.

The authors noted that this goes against an older figure of 10% to 25% lifetime risk.

Age changes the picture

A hazard ratio compares how fast an event happens in one group versus another over time. A value below 1 means a lower rate.

In the VA study, each added decade of age at diagnosis cut the risk of a flare by 24% (HR 0.76, 95% CI 0.6-0.9). So people diagnosed younger had higher risk.

A labeled illustration, not a prediction

No study in this review gives an absolute risk of a flare for a high 23andMe score. The table below is math only. It is not anyone’s predicted risk.

Illustration only	Out of 100 people	Not affected
A baseline of about 4 in 100	4	96
A hypothetical doubling of that baseline	8	92
A hypothetical tripling of that baseline	12	88

Even in the tripled example, most people never have a flare.

The sibling relative risk of 2.92 measured all pouch disease. It should not be stacked on top of a polygenic score.

The NHGRI explains that a polygenic risk score has no built-in baseline or time frame. It only shows where a person stands compared with others. Scores “will always be probabilities, not certainties”.

A “typical likelihood” result does not rule the condition out. A “higher than average” result does not make it certain.

Other factors also matter. The NIDDK lists low-fiber diets, diets high in red meat, lack of activity, NSAIDs (pain relievers such as ibuprofen), steroids, obesity and smoking as possible risk factors.

A primary care clinician can combine age, history and colonoscopy findings into a personal picture.

Section recap: The starting risk is small, around 4 out of 100 people with pouches. A gene label shifts that number only a little and never turns it into a sure thing.

4. Testing: what a 23andMe polygenic report is and what it is not

The 23andMe Diverticulitis report is listed among its “Powered by 23andMe Research” polygenic reports. It uses more than 19,000 variants.

Per the company’s own footnote, these research-based reports have not been reviewed by the FDA. They differ from a separate group of “Genetic Health Risks” reports that meet FDA rules.

The company lists the ancestries for which the report is thought to be relevant. These include East/Southeast Asian, European, Hispanic/Latino, South Asian and Sub-Saharan African/African American, among others.

The company’s disclaimer says the test is not meant to diagnose any disease. It also says results should not be used to make medical decisions.

The NHGRI adds that most gene studies have involved people of European ancestry. Scores may therefore be less accurate in other groups. Polygenic scores are not yet routine in clinical care, because practice guidelines are lacking.

A weather forecast is a useful comparison. A “70% chance of rain” helps planning, but it does not tell anyone whether it is raining now.

How diverticulitis is actually diagnosed

Question	23andMe polygenic report	Clinical care
What does it look at?	19,000+ common variants	Symptoms, examination and imaging
Can it find pouches or inflammation?	No, it does not diagnose disease	Yes, CT of the abdomen and pelvis is the preferred first test
Is it FDA-reviewed?	This report type has not been FDA-reviewed	Not applicable
What comes after recovery?	Nothing changes automatically	Colonoscopy in selected cases

The ACG guideline calls a CT scan essential to confirm a flare, above all at a first episode. After recovery, it recommends colonoscopy after a flare with complications. It suggests one after a simple flare with warning signs, or when colon cancer screening is not up to date.

The ASCRS guideline states that routine gene testing is not a reason on its own for planned surgery. It treats gene and family factors only as minor risk factors to discuss.

No clinical gene test is described in these guidelines for the common form. Clinical gene panels are a different tool, used when signs point to a rare support-tissue disorder.

Whether AncestryDNA or Color offers a diverticulitis-specific report was not checked for this article.

Anyone with such signs can ask for a referral to an ABGC-certified genetic counselor or a medical geneticist. The NSGC directory at NSGC.org lists counselors by location.

Section recap: A polygenic report ranks genetic tendency but cannot diagnose anything. Diagnosis relies on symptoms and CT scans, guided by a clinician.

5. Prevention: what cohort research says about diet, weight and activity

This is the most hopeful part of the research. Genetic tendency does not cancel out the effect of daily habits.

Lifestyle helps at every level of genetic risk

A 2025 study in Gut combined four long-term follow-up studies with a hospital biobank. It built a healthy lifestyle score from 179,564 people. The score counted five factors, which were not smoking, a healthy BMI, physical activity, fiber and less red meat.

People with all five healthy factors had about half the risk of those with none (HR 0.50, 95% CI 0.44-0.57). This held in both Black and White people in the Southern Community Cohort Study.

The key finding came from 36,077 people whose genes were tested. Each one-point gain in the lifestyle score lowered risk by a similar amount at every genetic risk level.

Genetic risk group (polygenic score)	Risk change per one-point gain in lifestyle score
Low	HR 0.89, about 11% lower
Middle	HR 0.86, about 14% lower
High	HR 0.87, about 13% lower

The authors concluded that a healthy lifestyle was linked to lower risk whatever a person’s genetic tendency. In the biobank, higher BMI raised risk across all genetic risk groups.

This study included women from the Nurses’ Health Studies. That makes it more useful for women than the men-only diet studies below.

The nuts and popcorn myth

The Health Professionals Follow-up Study followed 47,228 US men for 18 years. Men who ate nuts or popcorn often did not have a higher risk of flares.

Comparing at least twice a week with less than once a month, popcorn had an HR of 0.72. Nuts had an HR of 0.80, a borderline result. Corn showed no link.

None of these foods was linked to bleeding from the pouches. The authors said advice to avoid them should be rethought.

Eating pattern matters more than single foods

A later study of 46,295 men tracked 1,063 cases of flares. A Western pattern high in red meat, refined grains and high-fat dairy raised risk (HR 1.55). A prudent pattern rich in fruits, vegetables and whole grains lowered it (HR 0.74). Fiber and red meat explained most of the link.

What the 2026 guidelines recommend

The ACG guideline lists these prevention steps:

• Eat a healthy diet, without avoiding nuts, seeds, corn or popcorn.
• Stay active and keep a healthy weight.
• Avoid smoking and heavy drinking.
• Avoid regular NSAID use unless it is medically needed.

The ACG states that sticking to a healthy lifestyle is linked to about a 50% drop in risk. The ASCRS guideline gives similar conditional advice, including more fiber and less meat. It notes that nuts and seeds have not been linked to flares.

Think of the genes as the slope of a hill. Habits are the brakes, and they work on any slope.

Diet during an active flare is different and should follow the treating clinician’s advice. A primary care clinician or dietitian can fit these habits to any health problems a person already has.

Section recap: In a large 2025 study, healthy habits lowered the risk of flares by a similar amount at low, middle and high genetic risk. Nuts and popcorn do not need to be avoided.

6. Treatment landscape: antibiotics, observation and the LASER surgery trial

Care for diverticulitis has changed a great deal. Two 2026 guidelines now set the US standard, from the ACG and the ASCRS. They update past advice, including the 2020 ASCRS guideline.

Antibiotics are now used selectively

The ASCRS guideline says people with a healthy immune system treated at home for an uncomplicated (simple) flare may skip antibiotics at first. This is a strong recommendation based on high-quality evidence.

The ACG guideline suggests against routine antibiotics for low-risk, simple cases. It keeps them for high-risk signs, a weak immune system, frailty or unsafe home care.

Two randomized trials back this shift. In a randomized trial, chance decides which group each person joins.

Trial	Patients	Main result
DIABOLO, Netherlands	528 with a first uncomplicated episode	Median recovery 14 days with observation vs 12 days with antibiotics
DIABOLO outcomes	Same group	No significant difference in complications, recurrence, surgery, readmission or trial-recorded adverse events
AVOD, Sweden and Iceland	623 CT-verified patients	Perforation or abscess in 1.9% without antibiotics vs 1.0% with them

In DIABOLO, adverse events (any health problems logged during the trial) occurred in 48.5% of the watch-and-wait group and 54.5% of the antibiotic group. Hospital stay was shorter with watchful waiting, 2 days vs 3 days.

AVOD concluded that antibiotics neither sped healing nor prevented problems or repeat flares in simple cases.

Planned surgery: the LASER trial

The LASER trial randomly assigned 90 Finnish patients to planned sigmoid resection or non-surgical care. Sigmoid resection is surgery that removes the S-shaped last part of the colon. All had repeat, lasting painful or complicated flares.

At 4 years, repeat flares hit 6 of 38 (16%) after surgery vs 34 of 37 (92%) with non-surgical care. Quality-of-life scores were 115.3 vs 109.8. That gap was not statistically significant.

Of the non-surgical group, 14 of 44 (32%) had surgery within 4 years. Severe problems after surgery occurred in 10% vs 11%.

The authors concluded that surgery prevented repeat flares but did not improve quality of life at 4 years. These results do not apply to a first simple flare or to pouches alone.

The ASCRS guideline says planned surgery should be decided case by case. It weighs surgery risk, quality-of-life gain, ongoing symptoms and how often attacks come back. Young age at onset alone is not a reason for surgery.

Drugs to prevent flares and their approval status

Two phase 3 trials, the large final tests before approval, compared mesalamine with a placebo for 104 weeks after a flare. A placebo is a dummy pill with no drug in it. Mesalamine did not cut repeat flares or delay them. The authors stated that mesalamine is not recommended for this use.

In plain terms, no FDA-labeled drug to prevent flares was found. The details are below.

• FDA: LIALDA (mesalamine, NDA022000) was first approved on 2007-01-16. Its current label covers ulcerative colitis only.
• Health Canada: MEZAVANT (DIN 02297558) was first authorized on 2007-07-13. Its monograph lists ulcerative colitis only.
• Prevention drugs: An openFDA label search found no drug labeled to prevent diverticulitis.
• Canada check: No Health Canada-authorized drug for preventing flares was found (not fully checked).

The ASCRS guideline does not usually advise mesalamine, rifaximin or probiotics to reduce repeat flares. It says fiber plus rifaximin may be of value, a conditional suggestion based on low-quality evidence. Rifaximin’s approval status for pouch disease was not checked for this article.

Red flags that need prompt care

Seek prompt medical care for:

• Belly pain, often in the lower left, together with fever or chills.
• Nausea or vomiting with belly pain.
• Severe or worsening pain, rectal bleeding, or a rigid, very tender belly.

For severe symptoms, call 911. Antibiotic and surgery choices belong to the treating clinician, gut specialist or colon surgeon.

Section recap: Many simple flares can be treated without routine antibiotics. Surgery cuts repeat flares but did not clearly improve quality of life at 4 years, and no FDA-labeled drug to prevent attacks was found.

7. Family implications: siblings, children, and why cascade testing does not apply

Cascade testing means testing relatives for one known variant already found in the family. It works for single-gene conditions. The common form of diverticulitis has no single family variant to test for.

So the family history itself is the useful information. It is a reason to know the symptoms and share the history with a clinician.

What the numbers say for each relative

Relative	What research shows
Brother or sister	Relative risk 2.92 for diverticular disease vs the general population
Identical co-twin	Relative risk 14.5, vs 5.5 in fraternal twins
Parent or child	No parent-to-child relative risk was reported

The sibling figure covers all pouch disease, not just flares. It should not be used as a number for a parent’s risk or for children.

What children inherit

Each child gets a different, random mix of each parent’s gene variants. A parent’s polygenic score therefore does not predict a child’s score.

Like shuffling two decks of cards, each child gets a unique hand. The NHGRI notes that polygenic scores remain probabilities, not certainties.

Does a sibling’s surgery mean another sibling needs one?

No. The ASCRS guideline states that family history is not a reason on its own for planned colectomy, surgery to remove part of the colon. It is only a minor risk factor to discuss.

When a rare inherited disorder may be worth asking about

Rare support-tissue disorders have been tied to pouch disease. Unusual signs in a family may be worth raising with a clinician. Examples include very early onset, unusual hernias, very loose joints, blood vessel problems or kidney cysts.

This is general guidance, not a formal checklist. In that case, a referral to an ABGC-certified genetic counselor or medical geneticist is reasonable.

Section recap: Cascade testing does not fit a polygenic condition. Family history is the useful signal, and it does not by itself call for scans or surgery.

8. Insurance, privacy and family conversations: GINA and its gaps

A “higher than average” label can cause worry, even without symptoms. Knowing the legal protections can ease part of that worry.

United States: GINA

GINA, a 2008 federal law, protects against genetic discrimination in health insurance and jobs. Its definition of genetic information includes a person’s gene tests. It also includes family members’ tests and family medical history.

Area	Protected by GINA?
Private health insurance	Yes
Medicare, Medicaid, FEHB, Veterans Health Administration	Yes
TRICARE	Only limited protection
Employers with 15 or more employees	Yes
Employers with fewer than 15 employees	No
US military employment decisions	No, the military may use genetic information
Life, disability and long-term care insurance	No, though some states add protections

Canada: the Genetic Non-Discrimination Act

Canada’s Genetic Non-Discrimination Act received assent on 2017-05-04. It bars requiring a gene test, or its results, as a condition of goods, services or contracts.

It also bars collecting, using or sharing results without written consent. Health care workers and researchers are exempt. Penalties reach a $1,000,000 fine, up to 5 years in prison, or both.

The Supreme Court of Canada upheld the law in July 2020. Insurers, including life insurers, therefore cannot require gene test results.

The act protects gene test results only. It does not protect family history, a diagnosed condition or symptoms. A family history of the condition therefore may still have to be shared in Canada.

Talking with family

A shared family history is a fact, not a verdict. Talks can focus on symptoms to watch for and on habits that help everyone.

Sharing the history with a doctor is often more useful than sharing a raw gene score. It is also worth checking the privacy settings of any home DNA test account.

A benefits adviser can answer insurance questions. A genetic counselor can help plan family talks.

Section recap: GINA covers US health insurance and most jobs, but not life insurance. Canada’s law protects test results, not family history.

Frequently asked questions

Does a family history or a high genetic score mean a person will get diverticulitis?

No. Fewer than 5 out of 100 people with diverticulosis develop diverticulitis. A polygenic score is a probability, not a certainty. A clinician can put the result in personal context.

Will a parent’s children inherit diverticulitis risk?

Each child gets a different mix of variants, so a parent’s score does not predict a child’s. No study here reported a parent-to-child relative risk. Healthy habits lower risk at every genetic level.

Can a 23andMe result affect health or life insurance?

In the US, GINA protects against genetic discrimination in health insurance, including Medicare. It does not cover life, disability or long-term care insurance. In Canada, insurers cannot require gene test results.

Can an employer find out about a genetic result?

GINA bars employers with 15 or more employees from treating workers unfairly based on genetic information. Smaller employers and the US military are not covered. An employment lawyer can advise on specific cases.

Is a second opinion worth considering before planned surgery?

It can be. The ASCRS guideline says planned surgery should be decided case by case. In the LASER trial, surgery cut repeat flares but did not clearly improve quality of life at 4 years.

Summary

• Twin studies tie about 40% to 53% of the spread in diverticular disease risk to genes.
• Siblings of affected people have about 2.92 times the risk of pouch disease.
• Gene-mapping studies point to colon-wall tissue and how the bowel moves, through many small effects.
• The absolute risk stays low, at about 4 out of 100 people with pouches over 11 years.
• A healthy lifestyle was linked to lower risk at every level of genetic risk.
• Nuts, seeds and popcorn do not need to be avoided.
• Many simple flares do not need routine antibiotics, and surgery is decided case by case.
• GINA protects US health insurance and most jobs, but not life insurance.

A primary care clinician is the best next step for turning these findings into a personal plan.

This article is for educational purposes only. It does not replace medical care, diagnosis, or genetic counseling. For any decision about testing, treatment, or care, consult a licensed physician, a medical geneticist, or an ABGC-certified genetic counselor. In emergencies, call 911.

References

1. NIDDK (NIH). Definition & Facts and Symptoms & Causes of Diverticular Disease. https://www.niddk.nih.gov/health-information/digestive-diseases/diverticulosis-diverticulitis/definition-facts
2. Strate LL, et al. Heritability and familial aggregation of diverticular disease. Gastroenterology. 2013. https://pubmed.ncbi.nlm.nih.gov/23313967/
3. Granlund J, et al. The genetic influence on diverticular disease: a twin study. Aliment Pharmacol Ther. 2012. https://pubmed.ncbi.nlm.nih.gov/22432696/
4. Maguire LH, et al. Genome-wide association analyses identify 39 new susceptibility loci for diverticular disease. Nat Genet. 2018. With Sigurdsson S, et al. Nat Commun. 2017. https://pubmed.ncbi.nlm.nih.gov/30177863/
5. Neylan CJ, et al. Genome-wide association meta-analysis identifies 126 novel loci for diverticular disease. medRxiv preprint, not peer reviewed. 2025. https://www.medrxiv.org/content/10.1101/2025.03.27.25324777
6. Ma, Ha, et al. Lifestyle factors, genetic susceptibility and risk of incident diverticulitis. Gut. 2025. https://pubmed.ncbi.nlm.nih.gov/40592564/
7. Shahedi K, et al. Long-term risk of acute diverticulitis among patients with incidental diverticulosis. Clin Gastroenterol Hepatol. 2013. https://pubmed.ncbi.nlm.nih.gov/23856358/
8. Strate LL, et al. Nut, corn, and popcorn consumption and the incidence of diverticular disease. JAMA. 2008. https://pubmed.ncbi.nlm.nih.gov/18728264/
9. Strate LL, et al. Western dietary pattern increases, and prudent dietary pattern decreases, risk of incident diverticulitis. Gastroenterology. 2017. https://pubmed.ncbi.nlm.nih.gov/28065788/
10. Peery AF, Strate LL, Stollman N, et al. ACG Clinical Guideline: Colonic Diverticulitis. Am J Gastroenterol. 2026. https://doi.org/10.14309/ajg.0000000000004047
11. Hawkins, Bhama, Langenfeld, et al. ASCRS Clinical Practice Guidelines for the Management of Left-Sided Colonic Diverticulitis. Dis Colon Rectum. 2026. https://doi.org/10.1097/DCR.0000000000004382
12. Santos A, et al. Sigmoid resection vs conservative treatment after diverticulitis: 4-year analysis of the LASER trial. JAMA Surg. 2025. https://pubmed.ncbi.nlm.nih.gov/40202724/
13. Daniels L, et al. DIABOLO trial. Br J Surg. 2017. Chabok A, et al. AVOD trial. Br J Surg. 2012. https://pubmed.ncbi.nlm.nih.gov/27686365/
14. Raskin JB, et al. Mesalamine did not prevent recurrent diverticulitis in phase 3 controlled trials. Gastroenterology. 2014. FDA Drugs@FDA (LIALDA) and Health Canada Drug Product Database (MEZAVANT). https://pubmed.ncbi.nlm.nih.gov/25038431/, https://api.fda.gov/drug/drugsfda.json?search=application_number:NDA022000, https://health-products.canada.ca/dpd-bdpp/info?lang=eng&code=78289
15. NHGRI, Genetic Discrimination. US EEOC, Genetic Information Discrimination. Justice Laws Canada, Genetic Non-Discrimination Act. Cowan et al. Can Fam Physician. 2022. https://www.genome.gov/about-genomics/policy-issues/Genetic-Discrimination, https://www.eeoc.gov/genetic-information-discrimination, https://laws-lois.justice.gc.ca/eng/acts/G-2.5/FullText.html
16. NHGRI (genome.gov). Polygenic Risk Scores. https://www.genome.gov/Health/Genomics-and-Medicine/Polygenic-risk-scores
17. 23andMe clinician site. Genetic Reports: Health Predispositions. https://www.23andme.org/clinicians/genetic-reports/health-predispositions/

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Last updated: 2026-10-17

Author: Yu Mizuno (Editor-in-Chief, non-physician), GeneLumen editorial team. This article is a cross-analysis of 17 published research sources (tier 1=13 / tier 2=2, plus one preprint and one company page). Sources include NIDDK and NHGRI at the NIH, the US EEOC, FDA drug records, ACG and ASCRS guidelines, and PubMed-indexed studies.

This article is for educational purposes only. It does not replace medical care, diagnosis, or genetic counseling from a licensed physician, medical geneticist, or ABGC-certified genetic counselor. In emergencies, call 911.

Related: Genetic Diseases category

🇯🇵 For readers in Japan — a separate Japanese edition written for Japan’s healthcare system (not a translation): https://genelumen.com/ja/ja-genetic-diseases/diverticulitis-genetic-risk-twin-gwas-ja