Intestinal Diverticulosis: What It Is and How It Manifests

Did you see the word "diverticulosis" in a colonoscopy or CT report and already run through the worst-case scenarios in your mind? Let's sort this out in plain terms: most often it is an incidental finding, not a sentence. And no, diverticulosis and diverticulitis are not the same thing, even though they sound alike.

What colonic diverticulosis is

Diverticula are small pouches that bulge outward through weak areas of the colon wall. The mechanism is simple: the mucosa and submucosa are pushed through weakened spots in the muscular layer. Diverticulosis is the condition in which such pouches are present in the bowel.

Let's clarify right away what it is not: diverticulosis does not mean a "diseased bowel" and does not mean inflammation. Most people with diverticula have neither symptoms nor problems, and symptoms ever appear in only 10–15% of them.

Sigmoid and colonic diverticulosis: where diverticula form

The pouches most often form in the lower parts of the colon. In Western countries, the left side is predominantly affected—hence the frequent "sigmoid diverticulosis" in reports: the sigmoid colon is located on the lower left. In Asia, by contrast, the right side is more often affected, regardless of ethnicity. So "colonic diverticulosis" in a report indicates the section where pouches were found, not a separate diagnosis.

Diverticulosis and diverticular disease: what the difference is

Here are three words that are constantly confused. Diverticulosis means pouches are present but there are no symptoms. Diverticular disease means the pouches are already making themselves known: chronic symptoms, bleeding, inflammation, or its complications. Diverticulitis is inflammation of one or more pouches, which can start suddenly and sometimes leads to serious problems.

Causes and risk factors

Researchers have not yet named the exact cause. Genetics, lifestyle, and a number of additional factors are being discussed: a diet low in fiber and high in red meat, lack of physical activity, smoking, obesity, and use of certain medications—for example, nonsteroidal anti-inflammatory drugs and steroids. The role of bacteria and stool retained in a pouch and of changes in the gut microbiome is being studied separately.

Prevalence increases with age: in the United States, diverticulosis is present in more than one-third of people aged 50–59 and in more than two-thirds of those over 80. In Canada and the United States, it affects approximately 50% of people over 60. Before age 40 it is rare; before age 50 it is more common in men, and after 50 in women.

How diverticulosis manifests and how it is detected

Most often it does not manifest at all: the finding appears incidentally on colonoscopy or computed tomography performed for another reason. If symptoms do occur, they look like this:

• pain in the lower abdomen on the left (in a small number of people, on the right), which worsens after eating and subsides after a bowel movement or passing gas;
• constipation or diarrhea, abdominal bloating;
• blood in the stool;
• with inflammation—severe constant pain, high fever, blood or mucus from the anus, nausea and vomiting.

The symptoms of diverticular disease resemble those of other conditions, such as irritable bowel syndrome, so they cannot be distinguished "by eye." The doctor takes a history, performs an examination, and if necessary orders blood and stool tests, and for confirmation—colonoscopy or flexible sigmoidoscopy, CT, ultrasound, or MRI.

Possible complications and when to see a doctor

Rarely, diverticulitis leads to serious complications: accumulation of pus (abscess), intestinal obstruction, fistula—an abnormal connection between the bowel and another organ, such as the bladder or vagina—bowel perforation, and peritonitis. Diverticular bleeding occurs separately: a small vessel in the pouch wall ruptures, and the bleeding can be heavy, even life-threatening.

You should see a doctor if blood or mucus appears in the stool, pain intensifies or does not go away, high fever and chills persist, there is vomiting that prevents keeping fluids down, diarrhea lasting longer than 7 days, or vomiting lasting longer than 2 days.

The mere presence of diverticula is not a reason to call an ambulance. 103/112 are needed if there is severe abdominal pain together with vomiting, bloating, or inability to have a bowel movement and pass gas; heavy bleeding from the anus; confusion, pale or mottled skin, very high or very low temperature, shortness of breath or rapid breathing—these may be signs of sepsis.

This material is for reference: it helps you understand the report and ask your doctor the right questions, but it does not replace a consultation—the final word still belongs to the gastroenterologist.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer