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Diverticulosis happens when pouches (diverticula) form in the wall of the colon. If these pouches get inflamed or infected, it is called diverticulitis. Diverticulitis can be very painful.
Doctors aren't sure what causes diverticula in the colon (diverticulosis). But they think that a low-fibre diet may play a role. Without fibre to add bulk to the stool, the colon has to work harder than normal to push the stool forward. The pressure from this may cause pouches to form in weak spots along the colon.
Doctors aren't sure what causes diverticulitis. Bacteria grow in the pouches, and this can lead to inflammation or infection.
Symptoms of diverticulitis may last from a few hours to a week or more. Symptoms include:
Your doctor will ask about your symptoms and will examine you. He or she may do tests to see if you have an infection or to make sure that you don't have other problems. Tests may include:
The treatment you need depends on how bad your symptoms are. You may need to have only liquids at first, and then return to solid food when you start feeling better. Your doctor will give you medicines for pain and antibiotics. Take the antibiotics as directed. Do not stop taking them just because you feel better.
For mild cramps and belly pain:
You may need surgery only if diverticulitis doesn't get better with other treatment, or if you have problems such as long-lasting (chronic) pain, a bowel obstruction, a fistula, or a pocket of infection (abscess).
You may be able to prevent diverticulitis if you drink plenty of water, get regular exercise, and eat a high-fibre diet. A high-fibre diet includes whole grains, fresh fruits, and vegetables.
Doctors aren't sure what causes diverticulitis. Bacteria grow in the pouches (diverticula), and this can lead to inflammation or infection. Pressure may lead to a small perforation or tear in the wall of the intestine. Peritonitis, an infection of the lining of the abdominal wall, may develop if infection spills into the abdominal (peritoneal) cavity.
The reason diverticula form in the wall of the large intestine (colon) is not completely understood. Doctors think diverticula form when high pressure inside the colon pushes against weak spots in the colon wall. Uncoordinated movements of the colon can also contribute to the development of diverticula.
Normally, a diet with adequate fibre (also called roughage) produces stool that is bulky and can move easily through the colon. If a diet is low in fibre, the colon must exert more pressure than usual to move small, hard stool. A low-fibre diet also can increase the time stool remains in the bowel. This adds to the high pressure. Pouches may form when the high pressure pushes against weak spots in the colon where blood vessels pass through the muscle layer of the bowel wall to supply blood to the inner wall.
It is not known why some people who have these diverticula (a condition called diverticulosis) develop diverticulitis and others do not.
Symptoms of diverticulitis may last from a few hours to several days. These symptoms may include:
Complications also can cause symptoms. If an abnormal opening (fistula) develops between the colon and the vagina or the colon and the urethra, you may pass air or stool from the vagina or the urethra.
Other conditions, such as irritable bowel syndrome (IBS) or a urinary tract infection, may cause symptoms similar to diverticulitis.
Diverticulitis occurs when pouches (diverticula) that have developed in the wall of the large intestine (colon) become inflamed or infected. It is not clearly understood why 20 out of 100 people who have these pouches—a condition called diverticulosis—develop diverticulitis and the others do not.
In Western countries (North America and Europe), diverticulitis usually affects the left side of the colon (sigmoid colon).
Mild attacks of diverticulitis, with few symptoms or signs of infection or inflammation, sometimes heal without treatment. In most cases, a doctor recommends oral antibiotics to resolve an infection and a clear liquid diet to rest the bowel until inflammation goes away.
When infection and symptoms are severe, diverticulitis is treated in the hospital. Treatment includes antibiotics given in a vein (intravenous, or IV) and resting the bowel with IV fluids. If severe diverticulitis is not treated, complications such as an abscess or fistula may develop. Surgery often is needed to treat complications.
It is common to have lower abdominal pain after recovering from an attack of diverticulitis. But this pain is not always a return of diverticulitis. Less than half of people ever have a second diverticulitis attack. Of those who do have another attack, about half have the second attack within 1 year of their first one.footnote 1
The possibility of having diverticulitis increases with age.
You may be more likely to develop diverticulitis if you:
Call 911 or other emergency services immediately if the person has been bleeding from the anus and has signs of shock, which could mean that a diverticular pouch is bleeding (diverticular bleeding). Signs of shock include passing out or feeling very dizzy or light-headed.
Call your doctor immediately if you have pain in the abdomen that is in one spot (as opposed to general pain in the abdomen), especially if you also have:
Call your doctor immediately if you have:
Call your doctor if you:
Call your doctor if you are treating mild diverticulitis at home and:
It is not uncommon to have bloating, gas pressure, or mild abdominal (belly) pain. These can be caused by eating certain foods or by stress. Home treatment usually will take care of these symptoms. If home treatment does not help or if the symptoms become worse, see your doctor.
Your family doctor or general practitioner can diagnose and treat diverticulitis.
If further tests are needed, if your symptoms do not respond to treatment, or if you may need surgery, your doctor may refer you to a:
Your doctor will take a history and do a physical examination if diverticulitis is suspected. Depending on your symptoms, you may have one or more tests to rule out other medical problems that could be causing your symptoms. The extent of testing will depend on how bad your symptoms are and how long they have lasted.
These tests may be done any time you see your doctor about abdominal pain or other symptoms.
Depending on your symptoms, your doctor may want to do one or more of these tests.
See the topic Diverticular Bleeding for more information.
You may have a brief (acute) bout of diverticulitis that goes away after treatment with antibiotics and a liquid diet. But in some cases the condition occurs off and on (intermittently) over the long term (chronic). Treatment is the same in both cases, unless complications occur.
Treatment for diverticulitis depends on how bad your symptoms are. If the pain is mild, you are able to drink liquids, and you have no signs of complications, treatment may include:
If the pain is severe, you are not able to drink liquids, or you have complications of diverticulitis, a hospital stay is needed. Treatment will include:
Treatment may also include:
Most cases of promptly treated diverticulitis will improve in 2 to 3 days. If your doctor prescribed antibiotics, take them as directed. Do not stop taking them just because you feel better.
Treatment after recovery from an attack of diverticulitis is aimed at preventing another attack. Treatment may include:
In some cases, complications of diverticulitis, such as an abscess, perforation, or bowel obstruction, can occur. Surgery to remove the affected part of the intestine usually is needed to treat these conditions.
Non-urgent (elective) surgery also may be done for diverticulitis if you have had two or more severe attacks, are younger than age 40, or have an impaired immune system.
To help prevent diverticulitis:
Home treatment may help you control symptoms of diverticulitis or reduce the chance of having additional attacks of diverticulitis.
To reduce abdominal pain caused by mild diverticulitis:
When you are feeling better, you can do some things to help prevent another attack. You may want to:
Do not use laxatives or enemas unless your doctor prescribes them. If you use laxatives too often, you can become dependent on them for bowel movements. If you are having a sudden (acute) attack of diverticulitis, laxatives or enemas can make the pain worse.
Medicines to stop infection and to control symptoms often are used to treat attacks of diverticulitis.
Medicines are not used to prevent future attacks of diverticulitis. Prevention depends on increasing the amount of fibre in your diet and practising healthy bowel habits.
Surgery for diverticulitis involves removing the diseased part of the colon. You may decide to have surgery for diverticulitis if you have:
Surgery for diverticulitis, in which the infected part of the colon is removed, may be required if you have complications, including:
Overall, fewer than 6 out of 100 people who have diverticulitis need surgery.footnote 3
Surgical treatment involves removing the diseased part of the large intestine (partial colectomy) and reconnecting the remaining parts. Depending on the severity and nature of the symptoms, more than one surgery may be needed to correct the problem. When multiple surgeries are needed, the person usually has a colostomy during the time between surgeries. A colostomy is a surgical procedure in which the upper part of the intestine is sewn to an opening made in the skin of the abdomen. Stool passes out of the body at this opening and into a disposable bag. Usually the colostomy is removed at a later time and the intestine is reconnected.
Surgical treatment of diverticulitis, called bowel resection, involves the removal of the diseased part of the large intestine.
People who have mild, brief attacks and who are willing to try long-term dietary changes may be able to avoid surgery. See the Prevention section of this topic for more information on diet.
If you have multiple attacks of diverticulitis, surgery may be appropriate.
In some cases of diverticulitis, a pocket of infection (abscess) in the abdomen heals on its own. At other times it can be drained without surgery. A needle is passed through the skin into the abscess, and the liquid containing the infection is drained. A computed tomography (CT) scan is used to help the doctor guide the needle into the abscess. Sometimes a plastic drain is placed temporarily in the abdomen to drain the abscess.
A blocked colon can sometimes be treated with bowel rest. You are not given anything to eat but instead receive fluids and nutrients through a tube connected to a vein. Suction through a tube placed in the nose and down into the stomach may be needed to keep the stomach emptied of digestive juices.
After 2 to 3 days of bowel rest, you are given something to eat. If the obstruction has cleared up, no surgery is needed. If the obstruction remains, bowel rest may be continued. If repeated periods of bowel rest fail to clear up the obstruction, surgery to remove the diseased part of the colon may be considered.
CitationsHumes D, Spiller RC (2016). Colonic diverticular disease: Medical treatments for acute diverticulitis. BMJ Clinical Evidence. http://clinicalevidence.bmj.com/x/systematic-review/0405/overview.html. Accessed April 14, 2016.Strate LL, et al. (2011). Use of aspirin or nonsteroidal anti-inflammatory drugs increases risk for diverticulitis and diverticular bleeding. Gastroenterology, 140(5): 1427–1433.Harford WV (2010). Diverticulosis, diverticulitis, and appendicitis. In EG Nabel, ed., ACP Medicine, section 4, chap. 12. Hamilton, ON: BC Decker. Other Works ConsultedFox JM, Stollman NH (2010). Diverticular disease of the colon. In M Feldman et al., eds., Sleisenger and Fordtran's Gastrointestinal and Liver Disease, 9th ed., vol. 2, pp. 2073–2089. Philadelphia: Saunders.Travis AC, Blumberg RS (2012). Diverticular disease of the colon. In NJ Greenberger et al., eds., Current Diagnosis and Treatment: Gastroenterology, Hepatology, and Endoscopy, 2nd ed., pp. 259–272. New York: McGraw-Hill.
Current as of: February 10, 2021
Author: Healthwise StaffMedical Review: Adam Husney MD - Family MedicineAnne C. Poinier MD - Internal MedicineE. Gregory Thompson MD - Internal MedicineJerome B. Simon MD, FRCPC, FACP - Gastroenterology
Current as of: February 10, 2021
Author: Healthwise Staff
Medical Review:Adam Husney MD - Family Medicine & Anne C. Poinier MD - Internal Medicine & E. Gregory Thompson MD - Internal Medicine & Jerome B. Simon MD, FRCPC, FACP - Gastroenterology
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