Archive for the ‘Diverticular disease information’ Category

Diverticular Disease: Progression, Smoking and Nicotine

Sunday, April 14th, 2019


Diverticular disease (DD) can progress from changes in the gut nerves and muscles to formation of diverticula (diverticulosis), to symptoms of colon dysfunction, to infections and inflammation (diverticulitis), to chronic symptoms, and to serious abdominal complications. The number of sufferers along this pathway diminishes greatly at every stage, only a minority ever need surgical treatment. On the other hand, progression and ageing go hand in hand.

The causes and risk factors of progression after diverticulosis are as varied as the people with DD.  Nobody knows what brings on diverticulitis which can be a gateway to problems. Historically, a diet low in fibre was thought to be responsible for all of the disease spectrum and could be easily remedied. This is no longer accepted. In the second half of the 20th century nobody considered an effect of smoking on the gut. Most Western adults smoked despite the risks of lung cancer and heart disease. Cigarettes had calmed the soldiers of the war, they were glamorous and macho, and nicotine was strongly addictive.

Cigarette use was aligned much closer to the appearance of DD in the world than diets which were variable and often assumed. Articles on this website in 2012 and 2013 have details of this epidemiology and also explain the pharmacology of nicotine where chronic use can cause the damage to the colon characteristic of DD.

Diverticula on the colon have to be identified before a diagnosis of the disease can be made. This happens in a hospital setting when symptoms or severe illness leads to investigative scans, x-rays or colonoscopies. Diverticula have already been formed then. The development of diverticula was described by interested pathologists early in the 20th century. Recent genetic and epidemiology research confirms that nerve and collagen changes are involved (1,2). These are the chronic effects of nicotine.

Hospital researchers have used diagnosed patients and their memories to produce “risk factors” and “associations” for DD based mainly on diets. Now, screening for colon cancer by colonoscopy around 50 years of age uncovers symptom-free diverticula. Participants can provide data on their lifestyles. Including smoking is a new opportunity to see if this was relevant to the presence or absence of diverticula. Also, increasing numbers of surveys are providing clinical evidence that cigarette smoking has a major effect on DD and its potential progression.


Data about smoking in 18-20 year old military conscripts in 1969-1970 was compared with Swedish national registers in 2009. Smoking increased the diagnosis of DD (3). The use of tobacco was greater in the 41.7% of colonoscopy outpatients found to have diverticula. The traditional risk factors for the presence of diverticula (low dietary fibre, constipation, red meat intake, low physical activity) were not confirmed (4).These authors thought that diverticula were most certainly present for many years before they were observed. Other American researchers (5) also considered that diverticulosis was longstanding before it was revealed. Two Japanese studies (6,7) related smoking to finding diverticula in outpatients. A history of smoking was revealed in Ulcerative Colitis patients who had diverticulosis (8). Recently in China (9) smoking was associated with diverticula in men (odds ratio = 2.14) and even more so in women (odds ratio = 10.2). Pooling together the data from several surveys (meta-analysis)  increases the validity of results. Two such studies (10,11) implicated smoking with diverticulosis and also increased risk of complications of the disease.


Past and current smokers had increased risk of symptomatic disease in Swedish women (12). In Swedish men, heavy smokers had increased risk of developing symptoms and there was some evidence of a dose/response relationship compared with non-smokers (13). The risk of changing from diverticulosis to diverticulitis was significantly higher in cigarette smokers in a report from Italy (14). Red meat was associated with increased risk of diverticulitis (15) but red meat eaters smoked more, used NSAID drugs and paracetamol, and had less vigorous exercise.


Present and previous smoking increased the risk for women of hospital admission for acute diverticulitis (16) and recurrent episodes (17). Compared with patients with no or minor symptoms, smoking was associated with hospital admissions because of complicated diverticulitis and severe infections (18,19).  Health conscious participants were used in a study by Crowe et al (20) to compare hospital and death records of DD between vegetarians and non-vegetarians. Smoking levels were only between 10% and 15%. Vegetarians and high dietary fibre intake gave a lower risk of hospital admission than meat eaters, but the vegetarians were younger. Compared with non-smokers, the increased risks for former smokers, light and heavy smokers were 31%, 34% and 86% respectively.


A Canadian survey of patients who underwent a partial colectomy found that current and former smokers had increased risk of surgery compared with non-smokers (21). Smoking was a risk factor for leakage of the join in the colon after part of it had been removed (22).

Removal of the sigmoid colon affected by DD was needed at a younger age in smokers compared with non-smokers, and the complications had developed more rapidly in smokers (23).


Some studies have not found any link between smoking and DD (24,25,26,27). These can be difficult to assess with gaps in details such as patient selection and their particulars, and ages. End points can be right sided disease or bleeding. Bleeding has so far not been related to smoking, but age, condition of blood vessels and drug side effects are relevant (28). The most quoted study is that of Aldoori et al (29) and their analysis of US male health professionals followed since 1986. In the 4 years between 1988 and 1992 there were 500 new cases of DD, 382 with symptoms and 118 without. Smoking was positively associated with the risk of symptoms, increasing with the number of cigarettes smoked per day and decreasing with the time since stopping smoking. These results were attenuated when dietary data was included in the analysis. The authors concluded that smoking was not associated with any substantial increased risk of symptomatic DD.  Another recent statistical assessment of the same group of health professionals found that smoking was independently associated with increased risk of diverticulitis (30).


This collection of reports is not exhaustive and more studies are likely. Some reviewers do not include data but an author’s opinion is cited. A mixture of positive and negative results is also found for other risk factors for DD. Bohm (31) emphasises the importance of differentiating risk factors between those for diverticulosis and for the other effects of the disease. This separation has been attempted here. The end point of a study is also relevant. For example, eating nuts, grains, corn and popcorn had no effect on hospital admissions for complications. Dietary avoidance of these foods was dismissed as irrelevant (32), but the long-standing avoidance of these foods for DD was based on pain. Many patients suffer from chronic and severe pain outside the hospital setting which is rarely researched. In fact, information about less serious symptoms and their treatment dealt with at primary care level is largely absent (33).

Age, sex and genetics are risk factors which cannot be changed, but many lifestyle choices, co-existing diseases and drug treatments also affect DD. Increasing opinion is that diverticula take years to form and are evident through symptoms a long time, even decades, after their cause by smoking. The cause of DD is distinct from many other factors which cause symptoms and complications. However, smoking is detrimental to all aspects of the disease and this should be reflected strongly in patient information.

Computer statistical assessments are used to uncover factors relevant to diseases, symptoms and progression, but the data used is subject to human choices and interpretation of results. The effect of smoking on DD was only included as a confounding factoring in studies relatively recently. Are older dietary studies still relevant if this was not included? The article by Labos (34) and its on-line comments are recommended reading on the subject. He considers a result found in several patient populations carries weight when the trials cannot be accurately replicated. In the case of smoking and DD, there is world-wide epidemiology, the pharmacology of chronic nicotine use and now, increasing clinical evidence of its profound effects.

The effect of smoking on DD and other diseases will be more difficult to asses in the future when people replace tobacco cigarettes (smoking) with e-cigarettes (vaping) for their nicotine fix. Many countries have banned e-cigarettes but some official organisations and powerful charities seem to be advising their use. Avoiding the carcinogenic chemicals from tobacco smoke is welcomed to reduce the risks of cancer, but people are then classed as ‘non smokers’ in surveys. The number of smokers will reduce, but the effects of continued use of nicotine should not be dismissed lightly. E-cigarettes are not regulated and long-term effects have still to be revealed. E-cigarettes are not medical devices, they will not overcome addiction to nicotine without commitment, determination and any help available. Retail outlets are increasing to make vaping commonplace and accessible. Its use by under 18s is increasing. Tobacco companies view e-cigarettes as their next generation products and aim to increase promotion and sales, just like they did in the mid 20th century for cigarette smoking.

Déjà vu.

© Mary Griffiths 2019


1.      Schafmayer C. et al. Genome-wide association analysis of diverticular disease points towards neuromuscular, connective tissue and epithelial pathomechanisms. Gut, 2019, Jan, 19th Epub.

2.      Broad JB et al. Diverticulosis and nine connective tissue disorders: epidemiological support for an association. Connect Tissue Res. 2019, Feb 5th. Epub.

3.      Jarbrink-Sehgal ME et al. Lifestyle factors in late adolescence associated with later development of diverticular disease requiring hospitalization. Clin Gastroenterol Hepatol. 2018, 16, 1474.

4.      Peery AF. et al. A high-fiber diet does not protect against asymptomatic diverticulosis. Gastroenterology, 2012, 142, 266.

5.      Strate LL. Diverticulosis and dietary fiber: rethinking the relationship. Gastroenterology, 2012, 142,205.

6.      Tarao K. et al. Recent trends in colonic diverticulosis in Yokohama City: a possibility of changing to a more western profile. Intern med, 2015, 54, 2545.

7.      Nagata N. et al. Alcohol and smoking affect risk of uncomplicated colonic diverticulosis in Japan. PloS One, 2013, 8, e81137.

8.      Kinnucan J. et al. U.S. patients with ulcerative colitis do not have a decreased risk of diverticulosis. Inflamm Bowel Dis. 2015, 21, 2154.

9.      Yang F. et al. Sex differences in risk factors of uncomplicated colonic diverticulosis in a metropolitan area from Northern China. Sci Rep. 2018, 8, 138.

10.  Wijarnpreecha K. et al. Smoking and risk of colonic diverticulosis: a meta-analysis. J Postgrad Med. 2018, 64, 35.

11.  Aune D. et al. Tobacco smoking and the risk of diverticular disease – a systematic review and meta-analysis of prospective studies. Colorectal Dis. 2017, 19, 621.

12.  Hjern F. et al. Smoking and the risk of diverticular disease in women. Br J Surg. 2011, 98, 997.

13.  Humes DJ. et al. PTU-230 Smoking and the risk of symptomatic diverticular disease: a Swedish population based cohort study. Dis Colon Rectum. 2016, 59, 110.

14.  Usai P. et al. cigarette smoking and appendectomy: effect on clinical course of diverticulosis. Dig Liver Dis. 2011, 43, 98.

15.  Cao Y. et al. Meat intake and risk of diverticulitis among men. Gut, 2018, 67, 466.

16.  Jamal Talabani A. et al. Risk factors of admission for acute colonic diverticulitis in a population-based cohort study: The North Trondelag Health Study, Norway. World J Gastroenterol. 2016, 22, 10663.

17.  El-Sayed C. et al. Risk of recurrent disease and surgery following an admission for acute diverticulitis. Dis Colon Rectum. 2018, 61, 382.

18.  Papagrigoriadis S. et al. Smoking may be associated with complications in diverticular disease, Br J Surg. 1999, 86, 923.

19.  McGarr S. et al. Cigarette smoking increases the risk of infectious complications associated with diverticular disease of the colon. Am J Gastroenterol, 2000, 95, 2543.

20.  Crowe FL. et al. Diet and risk of diverticular disease in Oxford cohort of European prospective investigation into cancer and nutrition (EPIC): prospective study of British vegetarians and non-vegetarians. BMJ, 2011, 343, d4131.

21.  Diamant MJ. et al. Smoking is associated with an increased risk for surgery in diverticulitis: a case control study. PLoSOne 2016, 11, e0153871.

22.  Baucom RB. et al. Smoking as dominant risk factor for anastomotic leak after left colon resection. Am J Surg. 2015, 210, 1.

23.  Turunen P. et al. Smoking increases the incidence of complicated diverticular disease of the sigmoid colon. Scandinavian Journal of Surgery. 2010, 99, 14.

24.  Storz C. et al. Characteristics and associated risk factors of diverticular disease assessed by magnetic resonance imaging in subjects from a Western general population. Eur Radiol. 2018, 29, 1094.

25.  Adamova Z. et al. Recurrent diverticulitis – risk factors. Rozhi Chir, 2013, 92, 563.

26.  Jamieson CG. et al. An investigation into the relationship between cigarette smoking and diverticular disease of the colon.  Can J Gastroenterol. 1990, 4, 193.

27.  Lin OS. et al. Dietary habits and right sided colonic diverticulosis. Dis colon Rectum. 2000, 43, 1412.

28.  Jansen A. et al. Risk factors for colonic diverticular bleeding: a Westernised community based hospital study. World J Gastroenterol. 2009, 15, 457.

29.  Aldoori WH. et al. A prospective study of alcohol, smoking, caffeine, and the risk of symptomatic diverticular disease in men. Ann Epidemiol 1995, 5, 221.

30.  Liu PH. et al. Adherence to a healthy lifestyle is associated with a lower risk of diverticulitis among men. Am J Gastroenterol. 2017, 112, 1868.

31.  Bohm SK. Risk factors for diverticulosis, diverticulitis, diverticular perforation and bleeding: a plea for more subtle history taking. Viszeralmedizin, 2015, 31, 84.

32.  Strate LL. et al. Nut, corn and popcorn consumption and the incidence of diverticular disease. JAMA , 2008, 300, 907.

33.  Humes DJ. Changing epidemiology: does it increase our understanding? Dig Dis. 2012, 30, 6.

34.  Labos C. Epidemiology: separating the wheat from the chaff. Aug 14th 2018.

Diverticular disease AND/OR irritable bowel syndrome

Friday, June 29th, 2018

Information about diverticular disease (DD) is available in fact sheets on many internet sites, but these should be assessed. Is it up to date, does it help day-to-day problems, is it a charity or a business? Discussions on forums show a variety of experiences of DD and no general approach on what can be done to help. DD is sometimes mentioned by charities which support younger people with, for example, Crohn’s and ulcerative colitis (IBD) or Irritable Bowel Syndrome (IBS). In the last few years some people with DD have been told that they also have IBS. This can be very confusing because DD and IBS are different complaints sometimes with conflicting treatments and certainly different potential outcomes. Some researchers propose that any symptoms without diverticulitis must be IBS. This ignores or denies the colon damage which resulted in diverticula forming. Sources of information about IBS do not cover an IBS/DD diagnosis, never mind any differences which should be considered. (more…)

The Microbiome in Diverticular Disease

Thursday, November 10th, 2016

New techniques which identify individual species have lead to an explosion of research into the role of bacteria in the colon. The terms ‘microbiota’ (the bacteria) and ‘microbiome’ (the collection of bacteria) are widely used. Some researchers consider the microbiome as equivalent to a body organ. It is certainly a significant, integral and specific part of the digestive system in man and animals. In protein-eating humans the microbiome is in the caecum, the first bag-like part of the large intestine which receives the residues of digestion and has enzymes which degrade amino acids from proteins. In herbivores the microbiome is in an earlier part of the digestive system to deal with large quantities of plant material to extract maximum nutrients for its host with enzymes to synthesise amino acids (1). The microbiome in humans can have both beneficial and unhelpful effects. Its position in the human body and the role of an associated appendix had not been considered apart from the letter on this website (2). The appendix is no longer considered a vestigial organ (3), contains extremely variable bacteria (4) and may be involved in microbiome changes (5).

Differences in the bacteria present in the microbiome have been found in conditions  such as obesity, autoimmune diseases, autism and bowel disease including diverticular disease (DD). The microbiome and its surrounding immune system are linked (6).

  • Is the microbiome content a cause or an effect of a disease?
  • Is the presence of a specific organism significant?
  • Could the microbiome be changed to treat a disease?

These are the questions research is trying to answer. Bacteria will only survive and flourish if the conditions and nutrients are right for the species. There is great variation both between and within people, with age and even with geographical location. So far only diet appears to make a difference (1, 7). Does the microbiome match dietary residues and the disease affect diet? (more…)

Diverticular Disease: Genetics and Collagen

Thursday, July 9th, 2015

Compared with other diseases, advancements in science and technology left diverticular disease (DD) behind decades ago. Worldwide occurrence, poor quality of life, level of mortality and healthcare costs should have generated far more research effort. Preoccupation with dietary fibre levels, constipation and ageing has and still is stunting research. Fibre levels have benefits for constipation and symptoms but research into cause, prevention and other treatments has been overtaken by the necessary investigations into the surgical rescue of DD effects. Recently valid trials and surveys have disputed traditional thinking about a dietary cause and revealed a genetic factor. (more…)

Diverticular Disease And Colon Cancer

Thursday, April 3rd, 2014

Does having diverticular disease (DD) increase the risk of colon cancer (CC)?  One expert would say “yes” and another would answer “no”. Much depends on the design of studies, choice of patients, what data is fed into the computer for statistical analysis, interpretation of the results and what opinions and conclusions are made.

Research can be based on the occurrence of the two separate diseases, how many people with DD have CC and how many people with CC have DD (1). Comparison can be made with the levels of CC and DD which would be expected in the general population. Information can be expanded by including different types of cancerous lesions and their position in the colon. The diagnosis of DD is not so stable. Diverticulitis but not diverticulosis was indicated to be in a long-term causal relationship with increased risk of left-sided CC (2). However, these conditions at diagnosis can change. Diverticulitis can revert to diverticulosis with few further problems, or, diverticulosis can later progress to diverticulitis or even further to serious complications. This is a basic problem in DD research. (more…)

Diverticulitis: a wind of change

Sunday, December 2nd, 2012

There have been many changes over the years in the approach to diverticular disease (DD), even in the names used. Diverticular disease is the overall name. The presence of the grape-like diverticula on the outside of the colon results in a diagnosis of diverticulosis. Diverticulitis occurs when there is infection and inflammation of the diverticula but is often used when there are any symptoms caused by the disease.

Diverticulosis can have episodes of diverticulitis or complicated diverticulitis when problems such as bleeding, abscess, fistula or blockage need surgical treatment. This is a simplistic explanation of what might happen in DD in decreasing numbers, so that only a small fraction of people with DD ever need surgery. Any progression in the disease can stop and revert to symptomless diverticulosis at any time, some people with diverticulosis do not even know that they have it.

There has been confusion over many years about the symptoms with DD. (more…)

Colon Wall Muscles in Diverticular Disease

Sunday, September 2nd, 2012


Between the mucus producing lining and the outer layer of the colon wall, there are two major muscle systems. The inner circular muscles surround the colon, contraction can close the colon or they can act in waves to propel contents along. Between the appendix at the beginning and the rectum at the end of the colon, longitudinal muscles are gathered into three bands known as taenia. This arrangement allows contractions to shorten the colon and propel faeces without compressing them. Coordination between the two types of muscle can produce a variety of movements. An earthworm moving along soil is a good example to observe a similar system.


In the caecum, repeated circular muscle contractions mix the liquid contents (chyme). These change into backwards and forwards segmenting and propulsive movements to dry and move the mushy contents along the ascending and transverse lengths of the colon. Longitudinal muscles become more involved as faeces become more solid in the second, left side, of the colon. Occasional powerful contractions sweep faeces into the descending and sigmoid areas. Faeces are stored with the sigmoid area acting as a vertical warehouse with supporting arcs of circular muscle. Strong contractions of longitudinal muscles produce a concertina effect to push out colon contents on defaecation. The first half of the colon is controlled automatically by the vagus nerve from the brain. The left side has some local nerve reflexes and a person can have some influence such as when to defaecate.


Changes in the colon musculature in diverticular disease (DD) were described even before the early 20th century when DD was rare, (1) and in many reports since. Muscle abnormality and dysfunction persisted in the colon after resection of the areas with diverticula (2). Long sections of the left colon can change in appearance without any diverticula which may only occur years later. The muscular abnormalities are the primary pathogenic mechanisms of DD (3). DD is only diagnosed when diverticula are observed, changes in muscles have had little attention especially in areas without diverticula. (more…)

Diverticular Disease: Updated Epidemiology

Thursday, May 3rd, 2012

“Ideas, like living organisms, have their natural history, growing from conception through a more or less tumultuous adolescence and reproductive maturity to an old age, when they act as a bar to further progress. During this time they become so modified that their origin is obscured” Sir Richard Doll (1)

Looking at the occurrence of a disease in time and place, and assessing what might have influenced changes, is known as the science of epidemiology. The theory, that diverticular disease (DD) was caused by low levels of fibre in the diet, has been prominent for about 40 years. This was based on the rarity of DD in Uganda compared with Western countries such as Great Britain or the USA. It was assumed that high levels of fibre in the Ugandan diet protected people from DD and that an increase in dietary fibre would prevent DD and its symptoms would be eliminated. This was a conclusion too far. It ignored the rarity of DD in people eating very little fibre (2,3) and that vegetarians can get DD (4,5). There is no evidence that a high fibre diet prevents DD. The theory is so entrenched that if DD appears in a country then it is assumed that its inhabitants have changed from their normal to a low fibre western diet. This is particularly incongruous when applied to right-sided DD in the caecum and ascending colon. Even the theory’s originators thought low fibre levels could not be relevant to this area (6)

Data from post-mortems, mortality statistics and surveys can provide information on the occurrence of DD, each aspect contributing to the overall picture. Song et al. (7) showed how colonoscopy findings, over time, could plot a rising prevalence of DD in Korea. Jun and Stollman in 2002 (8) collected results from research papers on the % of patients with DD in series of examinations by colonoscopy or barium enema Xray. They used these results to show that changes in the prevalence of DD varied greatly in time and between countries. Searching through later research reports mainly in the PubMed website gives this type of information for many more countries. (References to these sources are too numerous to include here). The results fall into 4 distinct patterns of when DD appeared and how numbers have changed over time until 2010. (more…)

How many people have diverticular disease and symptoms

Wednesday, January 12th, 2011

Nearly every review of diverticular disease (DD) and some research papers begin with statistics about how many people have DD at different ages. Figures regularly quoted for Western countries are 5% of the population by the age of 40, 25% by the age of 60 and 65% at 85 years. Variations are also described such as 50% of the population over 60 years, or 1/3 to 1/2 of the population will get the disease. In England and Wales this works out at over 5 million people which would rise with the aging population.

Trying to find the sources of these figures (more…)

All in a name – medical terms

Thursday, September 9th, 2010


Diverticular disease is an umbrella term which covers the physical changes in the colon wall and the effects from diagnosis to life-threatening complications and all the different symptoms which result from the disease. The muscular deformity with the characteristic bulging hernia or pouches called diverticula is known as diverticulosis. This definition is of a visible physical abnormality and does not indicate the extent of damage to the colon or describe its effects. Some people do not know that they have diverticulosis but after diagnosis about ¾ of patients have some type of symptoms. (more…)