The colon, or large intestine, is a muscular tube that forms the last part of the digestive tract. Semi-liquid food waste (stool) from the small intestine enters the colon at the cecum (the beginning of the colon). The stool moves from the cecum to the ascending colon, across the transverse colon, to the descending colon, sigmoid colon, and lastly through the rectum and anus. As the stool travels, the colon absorbs water and solidifies it.
Diverticula are pouches that can form in the walls of your colon. A healthy colon is lined with muscles that help move stool through your colon, into your rectum, and out your body. Without enough fiber and water in your digestive system, stool becomes hard and pressure builds up inside your colon. Your colon’s muscles have to squeeze more to move harder stools through the colon. That extra pressure can cause the lining of the colon wall to bulge out into diverticula, and the resulting condition is called diverticulosis. This usually occurs in the lower left, or sigmoid, colon. You may not even know that you have diverticula, but they can cause mild cramping, bloating, and changes in your bowel habits, including constipation, diarrhea, urgency, or rectal bleeding.
Nearly half of Americans over 60 years of age have diverticulosis. Maintaining a healthy lifestyle, including a high-fiber diet, plenty of fluids, and daily exercise, can help you avoid complications from this condition.
Diverticulitis occurs when the diverticula become infected or inflamed. The exact cause is unknown, but it may occur when stool lodges in the openings of diverticula, causing the pouches to swell. Swelling or inflammation may make the wall of the pouch thinner, allowing bacteria from the bowel to infect the cells in the lining. Symptoms of diverticulitis include a change in your bowel habits, along with pain in your lower left abdomen, which may be severe or may last for several days. You may develop nausea, fever, and chills. If the infection and inflammation becomes severe, the diverticula may rupture, causing infection of the abdominal cavity (peritonitis).
Signs and Symptoms
Diverticulosis may cause a change in your bowel habits, including constipation, diarrhea, and urgency. Other symptoms include mild cramping, bloating, or rectal bleeding, if the inflammation causes a blood vessel to burst.
Symptoms of diverticulitis and infection include severe pain, fever, and chills.
Your doctor will do a complete “history and physical,” first asking you numerous questions about your diet and symptoms, and then examining you physically, including a rectal exam. Your stool may be examined for mucus or blood, even if these are not obvious to the naked eye.
Special imaging techniques can be used to view the colon. A barium enema, followed by an x-ray, can show abnormalities such as pouches in the wall or narrowing of the colon. The doctor may also perform a sigmoidoscopy, using a tiny, flexible scope inserted through your anus, to see the lower aspect of the colon, or a colonoscopy with a longer scope, to view your entire colon. During the procedure the doctor can remove tissue samples, if needed, for detailed examination.
If you are diagnosed with diverticulosis, it is important to take action as early as possible to prevent complications and improve the health of your bowels. This might be as easy as changing your diet, exercising, and/or starting medications.
The two main keys to controlling diverticulosis are increasing your liquid and fiber intake. Fiber absorbs water as it travels through your colon, helping your stool stay soft and move smoothly. Try to increase your fiber intake to 25 to 30 grams per day by eating more fruits, vegetables, and whole grains. (See our list of good food sources of fiber, at the end of this discussion.) Over-the-counter stool-bulking agents like Metamucil or bran may also help, but start slowly to prevent discomfort from bloating and gas. Some cases of diverticulosis may require stool softeners or antispasmodic medications for pain relief. Exercise will also help keep your digestive tract flowing and prevent constipation.
If you have a mild case of diverticulitis, it may be treated with a temporary liquid diet and oral antibiotics. Severe cases of infection may need hospitalization and IV (intravenous) and antibiotics. Once your colon has rested and the inflammation has resolved, you’ll start increasing the high-fiber foods in your diet. If other types of treatment don’t control the problem or if complications occur, surgery will be needed.
Colon Resection Surgery
If other treatments for diverticulitis do not control the inflammation and infection, your surgeon may perform a colon resection. During a colon resection, the surgeon removes (resects) the affected piece of colon and then sews the two new ends together (anastomosis). The repair is designed to maintain your colon’s normal tube-like shape, so you can regain your normal bowel movements. Colon resection may be done as open surgery, with an incision down your belly, or laparascopically. Laparoscopic surgery is done by making 4 or 5 small incisions and inserting instruments and a tiny camera to perform the surgery. A gas is used to inflate the belly and lift the abdominal wall away from the internal organs. Your surgeon will determine which option is best for you.
Colon Resection with Colostomy
If your colon is too inflamed or diseased and the surgeon cannot rejoin your colon with your rectum, the surgeon will create a colostomy, or a new opening for the colon on the outside of your abdomen for removal of waste. The colon is brought out through the opening and formed into a “stoma.” When you have a bowel movement, stool passes out through the stoma and into a colostomy bag or appliance. Often, once the inflammation has healed in a few months, you will undergo another surgery to re-attach your colon to your rectum and remove the colostomy. In some cases, the colostomy may be permanent.
Risks and Possible Complications of Colon Resection Surgery
- Injury to nearby organs
- A connection (anastomosis) that leaks or separates
- Possible colostomy
- Risks from anesthesia
- Blood clots