Diverticulosis is an intestinal condition characterized by the presence of small, abnormal sacs, or diverticula, in the wall of the colon. The sacs occur most frequently in the section of the large intestine just above the rectum called the sigmoid colon. There may be only a single sac (diverticulum) or there may be hundreds.

Diverticula occur when pressure in the colon pushes the inner layer of the intestinal wall through weak spots in the middle muscular layer and then pushes both the inner and outer layers outward to form pouches. Constipation appears to be a major cause of intestinal pressure.

Most patients with diverticulosis have no symptoms. When they do occur, symptoms include muscle spasms, mild pain, bloating, constipation and sometimes the appearance of blood in the stool. Patients with diverticulosis do not experience fever or other indications of infection.

When the sacs become infected, diverticulitis develops. Both diverticulosis and diverticulitis together are often referred to as diverticular disease. Diverticulosis becomes increasingly more likely to develop as a patient gets older.

Since most people with diverticulosis have no symptoms, the condition is usually detected during an imaging test for another gastrointestinal condition. When a patient is experiencing symptoms that suggest diverticulosis, a primary physician or gastroenterologist will normally collect a medical history, perform a physical examination and order blood tests and imaging tests. Imaging tests that may be used include barium enema, colonoscopy and sigmoidoscopy.

Diverticulosis is the presence of uninfected diverticula, or small, bulging, abnormal sacs, in the large intestine. The pouches develop mainly in the sigmoid colon, the last section of the large intestine.

The large intestine absorbs water as it moves fecal matter into the rectum to be excreted from the body. The sigmoid colon, located on the left side of the body, empties into the rectum.

In most cases, diverticula form due to pressure against weak spots that develop within the colon. In the United States and some other Western nations, the sigmoid colon is the most common area in which these sacs develop. By contrast, people in some Asian countries develop sacs in other parts of the colon (which may be due to diet). In very rare cases, the sacs may occur throughout the entire colon.

There may be only a single sac (diverticulum) or there may be hundreds. Most are between 0.1 centimeter (about 0.04 inch) and 1 centimeter (about 0.39 inch) in diameter, although they can exceed 2 centimeters (about 0.79 inch). Larger sacs are often caused by infection. Giant diverticula are rare and can range from 3 centimeters (slightly over an inch) to 15 centimeters (almost 6 inches) in diameter.

Diverticulosis is very common in the United States, especially in older adults. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), about 10 percent of Americans under the age of 40 years have diverticulosis. The condition exists in half of all Americans over the age of 60 years, according to the NIDDK. However, due to the lack of symptoms in most people, the precise incidence is not known.

In most cases, diverticulosis does not cause any complications. However, the presence of diverticula increases the risk of diverticulitis, which occurs when the sacs become infected. According to the NIDDK, between 10 and 25 percent of patients with diverticulosis will develop diverticulitis. Both diverticulosis and diverticulitis together are often referred to as diverticular disease.

Diverticulosis is characterized by the presence of small, abnormal pouches, or diverticula, in the intestinal wall. The pouches may be birth defects, particularly if they involve all the layers of the intestinal wall, but they most often develop as a person ages. The sacs can range in size from small to large and may occur singly (diverticulum) or in large numbers. Most often, diverticula are small and single.

Although diverticulosis refers specifically to the presence of diverticula in the colon, sacs may appear in the organ walls nearly anywhere in the digestive tract. Other forms of diverticula include:

• Zenker’s diverticula. These occur in the upper portion of the esophagus, near the pharynx. They are generally believed to be caused by motor esophageal disorders. Pouches may also develop in the mid or lower esophagus and may cause difficulty swallowing (dysphagia), coughing, bad breath (halitosis) and the regurgitation of undigested food that had been trapped in the diverticula.
  
  
• Gastric diverticula. These are pouches in the stomach. Those located near the opening of the esophagus are typically present at birth. Sacs located elsewhere in the stomach may result from peptic disorders.
  
  
• Meckel’s diverticula. These are sacs in the small intestine, usually near the end of the ileum and near the beginning of the colon. They are typically present at birth and may cause abdominal pain. They rarely cause rectal bleeding.
  
  
• Duodenal diverticula. Sacs in the duodenum are usually located near the opening of the common bile duct and pancreatic duct. They may contribute to the formation of gallstones or acute pancreatitis is some patients.

Diverticulosis is characterized by the presence of small, abnormal pouches, or diverticula, in the intestinal wall. They are usually caused by pressure that builds within the colon. Constipation appears to be a major cause of this intestinal pressure. The longer stool remains in the colon, the more pressure it places on the intestinal wall. Straining during a bowel movement increases this pressure even more. Spasms in the intestinal muscles as they try to push hardened stool through the colon further increase the pressure on the intestinal wall.

Not everyone has the same chance of developing diverticulosis. Risk factors for the condition include:

• Not eating enough fiber and drinking enough fluids. Fiber and water soften the stool and make it easier to pass, reducing pressure on the intestinal wall. When there is not enough fiber and water in the diet, the stool tends to be harder, leading to constipation. Diverticulosis occurs more often in areas where low-fiber diets are common, such as the United States, Europe and Australia. In rural areas of Africa and Asia, where diets tend to be rich in fiber, diverticulosis is rare.
  
  
• Age. Diverticulosis becomes increasingly more likely to develop as a patient gets older. The body becomes less efficient at waste removal and the elasticity and strength of the colon decrease with age, especially in the sigmoid colon.
  
  
• Heredity. There may be a genetic predisposition for diverticulosis. This means that a patient who has a family member with the disease may be more likely to develop it.
  
  
• Irritable bowel syndrome (IBS). Diverticulosis often occurs with IBS. The frequent intestinal spasms that may occur in IBS may increase the risk of developing diverticulosis.

Most patients with diverticulosis have no symptoms. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), less than 10 percent of diverticulosis patients experience symptoms. The location, size or number of diverticula does not seem to have any effect on the presence or severity of symptoms.

Patients with diverticulosis do not usually have a fever, an elevated white blood cell count or other signs of infection, which may indicate diverticulitis. Some patients with diverticulosis may experience various symptoms, including:

• Noticeable muscle spasms. Some patients may feel localized (occurring in a specific area) muscle spasms, usually on the lower left side of the abdomen.
  
  
• Pain. Some patients feel mild, crampy, localized pain or tenderness, typically in the lower left side of the abdomen. The pain generally comes and goes and may be made worse by eating. Bowel movements or flatulence may make the pain go away.
  
  
• Bloating or feelings of fullness. Patients may feel bloated or full. The abdomen, particularly on the lower left side, may feel full or tense to the touch.
  
  
• Constipation, diarrhea or flatulence. The stool of some patients may be abnormally hard or soft. Constipation is somewhat more common than diarrhea in people with diverticulosis. Some patients may pass a greater amount of gas.
  
  
• Intestinal bleeding. In rare cases, small arteries that are often located beside the diverticula may rupture, causing bleeding. This appears to occur more often near pouches on the right side of the colon (which is rare in the United States but more common in some Asian countries). Diverticular bleeding is generally sudden and painless. It results in noticeable amounts of bright red to maroon blood in the stool. This bleeding generally stops on its own, does not recur and requires no treatment. In the rare cases where it does not stop or recurs, treatment, possibly surgery to remove the diverticula, may be necessary.

Since most people with diverticulosis have no symptoms, the condition is usually detected during an imaging test for another gastrointestinal condition. When a patient is experiencing symptoms that suggest diverticulosis, a physician (often a gastroenterologist) will normally collect a medical history, perform a physical examination and order blood tests and imaging tests.

During the evaluation of medical history, patients will typically be asked about their bowel habits, symptoms, diet and any prescription and/or over-the-counter medications they may be taking. During the physical examination, the physician may press on the abdomen to check for fullness or tenderness and perform a digital rectal exam. This exam involves inserting a gloved, lubricated finger into the rectum to check for bleeding, blockage or tenderness. blood tests will usually be ordered to rule out infection.

The symptoms of diverticulosis and other gastrointestinal conditions, especially irritable bowel syndrome, are very similar. Because of this, the diagnosis of diverticulosis occurs only after imaging tests to look for the presence of diverticula. These tests are also important in ruling out the possibility of colon cancer. Imaging tests that may be used include:

• Barium x-ray. A special compound is consumed or inserted into the colon to make it visible in x-rays. This can be used to detect the pouches and is usually the first test performed. However, there may be a large margin of error with barium tests and further imaging tests are usually required.
  
  
• Colonoscopy. A narrow tube with a tiny camera is inserted into the rectum and through the colon while the patient is sedated. The image of the colon appears on a monitor for examination, allowing for the visual detection of diverticula.
  
  
• Sigmoidoscopy. This is similar to a colonoscopy, but only the sigmoid colon and sometimes part of the descending colon are examined for diverticula. The patient does not need to be sedated.
  
  
• Computed axial topography (CAT) scan. A series of x-rays taken from different angles to create a three-dimensional image of the colon may be used.

There is no cure for diverticulosis. Once diverticula are present, they do not go away. However, when there are no symptoms, as is usually the case, there is generally no need for treatment. Dietary changes, exercise and good bowel habits help to prevent the formation of the sacs and prevent and relieve any symptoms. When treated with these measures, symptoms usually go away after three to four days.

The most important therapy for diverticulosis is the intake of plenty of fiber and water. This can be accomplished by eating more fiber-rich foods, such as fruits and vegetables, or taking fiber supplements, such as bulking agents. It is important to drink increased amounts of fluids while increasing fiber intake. These increases should be gradual. Suddenly eating large amounts of fiber when the body is not used to it may make symptoms (e.g., flatulence) worse. People with diverticulosis may benefit from avoiding foods that may get caught in or irritate the diverticula, including nuts, popcorn hulls and large seeds (e.g., sunflower seeds).

Exercise helps to relieve the pressure in the colon and makes it easier to pass stool. Poor bowel habits increase the pressure in the colon. When patients feel the need to have a bowel movement, they are urged not to wait any longer than is necessary to find a toilet. A bowel movement should not be forced. It is best to allow plenty of time rather than increasing the pressure on the intestinal walls.

Medications are rarely needed for diverticulosis. When required or requested, the most common medications are pain relievers. Physicians may prescribe antispasmodic agents to calm muscle spasms for some patients.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following diverticulosis-related questions:

1. What caused my diverticula to form?
   
   
2. Do my diverticula seem to be the cause of my symptoms?
   
   
3. What kind of diverticula do I have?
   
   
4. How many diverticula do I have?
   
   
5. What can I do to prevent diverticulosis?
   
   
6. What dietary changes should I consider?
   
   
7. Do you recommend any form of exercise?
   
   
8. Are there any other lifestyle modifications I should make?
   
   
9. Will medications or surgery be necessary for my diverticulosis?
   
   
10. How many patients with diverticulosis have you treated?