What Is Diverticulitis?

To understand diverticulitis, we first need to look at what sets the stage for the condition: When tiny, bulging pockets (called diverticula) form in the colon, the condition is called colonic diverticulosis. These little pouches are formed from pressure on weak spots of the intestinal walls. When the diverticula become inflamed or infected, this is diverticulitis.

Symptoms of Diverticulosis and Diverticulitis

People with diverticulosis (pouches in the colon) usually do not have outward symptoms. Symptoms of diverticulitis (infection and inflammation of these pouches), however, are more noticeable. There may be abdominal distention, pain, and tenderness typically in the left lower abdomen, diarrhea, chills, and low-grade fever.

What Causes Diverticula to Form?

When muscles strain frequently to move hard stool through the colon, pressure builds, causing weak spots on the colon to bulge and become diverticula. Also, as the body ages, the outer layer of the intestinal wall thickens, causing the open space inside the colon to narrow. Stool then moves more slowly through the colon, also increasing the pressure. These diverticula are most common in the lower part of the large intestine (the sigmoid colon).

Diverticulosis vs. Diverticulitis

Having diverticulosis is very common and most people never know they have it. Half of all people older than 60 have diverticula. But only 10%-25% of people go on to develop diverticulitis. Diverticulitis typically develops when the pouches (diverticula) that are blocked with waste become inflamed, leading to perforation of the bowel wall and infection.

Diverticular Bleeding

When a hole develops between a pouch and a blood vessel, bleeding can occur. This can cause a large amount of blood to suddenly appear in your stool. This condition is typically painless and the bleeding usually stops on its own. However, in rare cases, bleeding can be severe enough to require a transfusion or surgery. If you experience bleeding, contact your doctor right away.

What's Fiber Got to Do With It?

A diet low in fiber can create hard stools and lead to constipation, which can result in straining during bowel movements. This creates the increased pressure inside the colon that contributes to the formation of diverticula. Adding more fiber to the diet can help prevent constipation and may decrease the risk for diverticula in the colon.

Your High-Fiber Choices

Luckily, you don't have to look hard to find an abundance of high-fiber foods. Fiber is found in fruits, vegetables, whole grains, and legumes (dried beans, peas, and lentils). Make smart food choices including brown rice and whole wheat pasta in place of the regular version. And add extra veggies to your favorite dishes -- pizza, stews, spaghetti sauce. The American Dietetic Association recommends getting 20-35 grams of fiber every day.

Diagnosing Diverticular Disease

Since diverticulosis doesn't always cause bothersome symptoms, it is sometimes only diagnosed when the patient is evaluated for another medical condition. The diverticula (pictured here in yellow) can be seen via X-ray or a colonoscopy. When diverticulitis leads to a painful abscess, an ultrasound and CT scan of the abdomen and pelvis can detect collections of pus.

Treatment for Diverticulosis

Many patients with diverticulosis have minimal or no symptoms and do not require specific treatment. A high-fiber diet and fiber supplements are recommended to prevent constipation and the formation of more diverticula.

When Diverticulitis Causes Mild Pain

Patients with mild symptoms, such as abdominal pain, may benefit from anti-spasmodic drugs such as chlordiazepoxide (Librax), dicyclomine (Bentyl), hyoscyamine (Levsin), atropine, scopolamine, phenobarbital, hyoscayamine (Donnatal), and diphenoxylate and atropine (Lomotil).

Treating Diverticulitis

When diverticulitis symptoms -- abdominal pain, cramps, and fever -- are mild, oral antibiotics are usually sufficient. When pain is more acute, a clear liquid diet to allow the colon and bowel to recover may also be prescribed. When pain is increasingly severe, or when there is high fever or the inability to drink liquids, a hospital stay may be necessary, along with intravenous antibiotics and cessation of food or drink for a few days.

Complications of Diverticulitis

When inflammation of the diverticula leads to a tear in the intestinal wall, as pictured here, pus can leak out into the abdominal area, causing peritonitis (a painful infection of the abdominal cavity), abscesses, intestinal obstruction, and an opening (called a fistula) between the bowel and the urinary tract.

When Surgery Is Necessary

Diverticulitis that does not respond to medical treatment requires surgical intervention. Surgery usually involves draining pus and removing the segment of the colon containing the diverticula. Removal of bleeding diverticula is necessary for patients with persistent bleeding. Surgery may also be necessary for any diverticula that erode into the bladder, causing severe, recurrent urine infections and passage of gas during urination, and to treat intestinal obstruction.

Preventing Diverticulitis?

Once formed, diverticula are permanent. And no treatment has been found to prevent complications of diverticular disease. But diets high in fiber increase stool bulk and prevent constipation, which may help prevent more diverticula from forming and worsening diverticulitis symptoms. What about seeds and nuts? There's no evidence these foods cause diverticulitis flares. But if you feel they trigger your symptoms, substitute them for other high-fiber foods. Drinking plenty of water and getting regular exercise may also help.

Related Reading

• Understanding Diverticular Disease
• When to Call the Doctor
• Surgery for Diverticulitis
• Constipation and Dietary Fiber
• Types of Fiber and Their Health Benefits
• Diet Tips for Digestive Disorders
• Digestive Disorders Community
• Video: Getting Your Fiber