Diverticular disease is the term that covers both diverticulosis and diverticulitis. While almost everyone has heard these terms, many people still mix up the difference between diverticulosis and diverticulitis. Furthermore, there is a lot of misinformation out there regarding these common conditions, so it’s time to review what is new in the world of diverticular disease!
Let’s start with some basics: The tiny pockets that occur on the outside of the colon that we call diverticula are actually better described as pseudodiverticula (false diverticula) due to the fact that they only contain the inner two layers of the colon wall, called the mucosa and submucosa.
These inner two layers that form the lining of the bowel become pseudodiverticula by herniating through small natural weak points in the muscle layer of the colon. The weak points exist as natural openings where small blood vessels called vasa recta penetrate the bowel wall to feed blood to the inner layers of the colon. For various reasons that we will cover below, the inner mucosal and submucosal layers of the colon can pop through these openings and luckily will become contained by the outermost layer of the colon (called serosa) to form a small pocket, now called a diverticula.
Since pseudodiverticula is a mouthful, people just refer to these pockets as diverticula. The condition of simply having these small pockets is called diverticulosis.
Diverticulosis is typically asymptomatic, but can also cause several symptoms. Minor symptoms of constipation and chronic left lower abdominal discomfort may be related to diverticulosis and are thought to be caused by altered colon motility (loss of normal movement), narrowing of the colon, loss of compliance (lack of “stretchiness”) of the left side of the colon, and mild inflammation of the bowel in the affected area. The symptoms of diverticulosis often overlap with symptoms of a condition called irritable bowel syndrome (IBS).
The more severe complications of diverticulosis are diverticular bleeding and diverticulitis.
Diverticular bleeding is typically painless and may present as massive bleeding. Fresh red blood is usually passed from the rectum as one of the small penetrating vasa recta arteries ruptures and bleeds into the bowel lumen (inside the colon). Diverticular bleeding often results in hospitalization, and may require blood transfusion and/or procedures to control bleeding such as colonoscopy, angiography with embolization, and even surgery if the bleeding does not stop. Fortunately, most cases of diverticular bleeding are self-limited, that is, the bleeding stops on its own and the treatment mainly consists of supportive care.
Diverticulitis is the term used to describe inflammation of a diverticula and the surrounding segment of colon. This is typically quite a painful process and is often associated with a fever, sometimes constipation, and decreased appetite. The abdominal pain from acute diverticulitis is often present in the mid lower abdomen, the left lower abdomen, or a combination of both of these sites.
Laboratory testing in acute diverticulitis will often reveal an elevated white blood cell count and elevated inflammatory markers such as C-reactive protein (CRP). A CT scan of the abdomen and pelvis is the diagnostic test of choice, and will reveal a thickened and inflamed bowel wall, often with inflammatory changes extending outside the bowel wall into the surrounding fatty tissues, and possibly with evidence of “microperforation” or other complications. Treatment typically involves antibiotics, bowel rest or a limited diet, and local management of any complications (such as draining an abscess). Eventually surgical resection may be needed in cases of complicated or recurrent diverticulitis.
Now that we have reviewed the basics, I would like to cover some of the common questions that I get asked by patients about diverticular disease.
How did I get diverticulosis?
Diverticulosis is often though of as a disease of Western society, and is associated with several diet and lifestyle factors. Most notably, diverticular disease is associated with a low-fiber diet, a diet high in processed foods and red meat, a sedentary lifestyle, obesity, and smoking.
However, diverticular disease also has a genetic component. It is likely that genetic factors and lifestyle factors both play a role in developing diverticular disease.
Age is also a factor: The older you become, the higher the likelihood that you will develop diverticulosis!
Is there a special diet to follow for diverticulosis?
Yes! To prevent diverticulosis, you should eat a high-fiber diet of mostly plants, whole grains, and legumes. A high-fiber diet means about 30 grams of fiber a day for women, and about 35 grams of fiber a day for men, but more is better (to a point).
However, a high-fiber diet is not the whole picture! It is also important to eat anti-inflammatory foods such as seeds, nuts, fish, and olive oil! Diverticular disease is an inflammatory process, and foods like red meat, processed meat (bacon etc.), and processed carbs (sweets, snack foods, fast foods, etc.) are pro-inflammatory and can cause issues like diverticulitis to occur more frequently.
Can I eat seeds and nuts if I have diverticulosis?
Yes you can! It is not necessary to avoid seed and nuts if you have diverticular disease. Probably the best evidence we have that seeds, nuts, corn, and popcorn do not cause complications in patients with diverticular disease comes from a study published in JAMA in 2008 showing that not only was intake of nuts, seeds, popcorn, and corn NOT associated with developing diverticulitis, but in fact the opposite was true. Eating more seeds, nuts, corn, and popcorn actually seemed to be associated with LESS of a chance of developing diverticulitis! These foods are thought to be somewhat anti-inflammatory, and therefore may protect against diverticulitis.
What other lifestyle factors should I consider if I have diverticulosis?
The big four things to consider with diverticular disease (and every other disease) are smoking, alcohol use, obesity, and exercise.
Smoking: Bad in every way and increases inflammation throughout the body. Smoking is associated with diverticulitis. Smoking is also associated with poor wound healing after surgery. Don’t do it! (If you’re serious about quitting, ask your primary care doctor for help.)
Alcohol: Not great for your colon and can sometimes cause inflammation in the bowel. To be enjoyed sparingly.
Obesity: Associated with total-body inflammation and correlated with diverticular disease. Increases risk of surgery if needed for diverticular disease. (If you suffer from obesity, the best time to start working on your weight was 10 years ago, and the second best time is today! Check out my simple starter plan here.)
Exercise: Aside from the role of exercise in weight loss, exercise also promotes a healthy colon, and can help keep your other healthy lifestyle changes in check by creating a positive-feedback cycle. Try to do a little exercise every day, or at least four days a week!
Does diverticulosis ever go away?
No, not really. Once the pockets are there, they don’t regress and disappear. They’re similar to wrinkles in that way. However, the goals are to prevent new diverticula from forming and to prevent the pockets that are there already from worsening or developing complications such as diverticulitis.
Following a healthy diet and lifestyle is still important, even if it won’t turn back time and remove the diverticula from your colon! In fact, it is estimated that you can reduce your risk of developing diverticulitis by up to 75% by following the basic diet and lifestyle advice above!
New knowledge about diverticular disease
| “Old School” | “New Knowledge” |
|---|---|
| Diverticulosis is caused by constipation | Diverticulosis may be associated with constipation but no causative role has been established |
| Diverticulosis is caused by a lack of dietary fiber | Diverticulosis is related to a low-fiber Western diet, but fiber may not be the most important factor |
| Seeds and nuts are dangerous and should be avoided! | Eat as many seeds and nuts as you want. The more the better actually! |
| Diverticular disease affects elderly people only | Diverticular disease is common in young people (especially men) and the prevalence is rising! |
| Diverticular disease just happens to people randomly | There is a strong genetic predisposition to diverticular disease. It might be your parents fault! |
| Diverticular disease is due to small pockets herniating through the colon wall, a purely mechanical process due to high pressures in the colon | Diverticular disease is an inflammatory condition, and there are chronic cellular changes found throughout the entire colon wall |
| Lifestyle and diet are not associated with diverticular disease | The Western diet and lifestyle (obesity, smoking, high red meat intake, alcohol use, and physical inactivity) dramatically increases the risk of diverticular disease! |
Summary
Diverticulosis and diverticulitis are very common diseases. Many people have mild cases of diverticular disease and never need medical attention, but there are several common complications of diverticulosis that do require medical attention and can be quite dangerous.
Overall, the paradigm is shifting and we are beginning to think of diverticular disease as a type of inflammatory condition with a genetic predisposition, rather that purely a mechanical problem related to constipation and high pressures in the colon.
Following a healthy diet and lifestyle can dramatically reduce your risk of suffering complications from diverticular disease, so make sure to eat your vegetables, limit processed foods and red meat, get a little exercise every day, stop smoking, and work on maintaining a normal body weight.