What is diverticulitis?

Diverticular disease is a very common disorder of the bowel in which small, abnormal pouches (diverticula) form in the wall of your colon (large intestine). Having diverticular disease without any symptoms is known as diverticulosis. However, if these pouches become inflamed or infected, it is called diverticulitis. The main risk factors for diverticular disease include increasing age and eating a western diet low in dietary fibre. The condition is virtually unheard of in Asia and Africa, where foods that are high in dietary fibre are the norm.

Lack of dietary fibre means increased pressure is needed to move the stools through your colon. If you have diverticular disease, you may not have any symptoms whatsoever and may not even be aware of it. Diverticulitis can range from a mild case, which makes you feel unwell, to a full-blown medical emergency, requiring hospitalisation.

fibre

Ingredients in food that are not digestible. They pass through the digestive system relatively unchanged and help to keep the digestive system healthy.

Causes

Your colon is a muscular tube that pushes waste matter down towards your rectum, to be expelled via your anus as stools. The colon uses rhythmic muscular contractions (peristalsis) to propel waste matter along, using its tough outer layer of muscle in a squeezing/pushing movement. The inner layer of your colon is lined with smoother, weaker tissue.

If you eat a diet that is rich in fibre, your stools are large and soft and easily pushed out of your body. If your diet is mainly processed foods that are low in dietary fibre, this can give you constipation, resulting in small, hard stools. These are difficult for your colon to move, needing extra effort and straining on your behalf. 

It is believed this straining can cause weak areas to appear in your colon wall, especially near where blood vessels emerge. Small pockets of the colon's inner lining get pushed through these weak areas as you strain. These are diverticula. They can form anywhere in the colon; however, it is more common for them to form on the left side of the abdomen (descending colon). 

As you age, the pressure from constipation can further weaken your intestinal walls, making it easier for diverticula to form. It is thought that a piece of hardened stool becoming trapped in your diverticula may trigger the infection of diverticulitis. Without treatment, severe complications (see below) may occur. 

Pain in lower left hand side of your abdomen.Diverticulitis is the inflammation of the diverticula formed in the colon wall as a result of constipation. 

Abdomen

The part of the body that lies between the chest and the pelvis.

Anus

The opening at the end of the anal canal, between the buttocks, through which faecal matter and intestinal gas exits the body.

fibre

Ingredients in food that are not digestible. They pass through the digestive system relatively unchanged and help to keep the digestive system healthy.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Inflammation

A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Rectum

The final part of the large intestine, leading to the anus.

Risk factors

Risk factors for diverticulitis include:

  • Having diverticular disease and a history of constipation;
  • Being over 50 years of age and eating mostly foods that are processed and low in fibre;
  • Living in a western nation, especially Australia, Europe or North America;
  • Being obese and physically inactive;
  • Being a smoker, and;
  • Using non-steroidal anti-inflammatory pain-relief medications (NSAIDs) such as ibuprofen.

fibre

Ingredients in food that are not digestible. They pass through the digestive system relatively unchanged and help to keep the digestive system healthy.

NSAIDs

Non-steroidal anti-inflammatory drugs are commonly used to manage arthritis-related pain and inflammation and other musculoskeletal disorders. NSAIDs include aspirin and ibuprofen.

Signs and symptoms

Symptoms of diverticulitis include some or all of:

  • Constant, sharp pain in the lower left-hand side of your abdomen;
  • Nausea and vomiting;
  • Fever above 38ºC;
  • Bloated abdomen, and;
  • Blood in your stool.

Diverticulitis can cause severe pain in the lower left - hand side of your abdomen.Diverticulitis can cause sharp pain in the lower left-hand side of the abdomen. 

Abdomen

The part of the body that lies between the chest and the pelvis.

Fever

An increase in body temperature above the normal temperature range. Fever is often caused by the body's immune reaction to infection.

Methods for diagnosis

Diverticular disease often goes undiagnosed and you may only discover you have the condition if you have an acute episode of diverticulitis. In fact, the presence of diverticula are often only discovered during investigative procedures for another bowel condition. 

Medical history

Your doctor may ask about your complete health history, including your diet and exercise status.

Physical examination

Your doctor will press the outside of your abdomen to find areas of pain.

Blood tests

A full blood count can be used to screen for infection by measuring your white blood cell count. Other blood tests may include liver, pancreatic and kidney function tests, as well as inflammation markers. If other conditions are suspected, blood tests may be ordered to help exclude these.   

Stool culture

A stool microscopy, culture and sensitivity is used to check if there are harmful bacteria in your faeces. You will be given a sterile container to provide a fresh stool sample. In the lab, a scientist will look for bacteria under a microscope and place some of your stool onto a special gel (agar) plate, which will selectively grow certain bacteria. The stool may also be tested for the presence of blood.

Computerised tomography (CT) scan

CT scans send X-ray beams from multiple angles using a machine that circles your body. This allows the machine to generate cross-sectional images of your internal organs. Often a contrast dye will be injected into your veins before the scan, and/or ingested or given as an enema if the scan is of the abdominal area, to help get a clearer picture of the digestive system. Abdominal scans also require fasting for 2-4 hours prior. The whole procedure takes about 30 minutes. A CT scan can help diagnose diverticulitis and its potential complications.

Barium enema

A barium enema is a diagnostic procedure that uses a contrasting barium dye and X-ray to examine your bowels. Before the procedure, the bowel will be prepared by being flushed out with an oral laxative solution and/or enema. A barium-filled tube is then inserted into the anus and the fluid released into the colon. Air will be pumped in to ensure the fluid reaches the corners of the bowel. An X-ray is then taken of the inflated bowel and it may show if diverticula are present.

Colonoscopy

A colonoscopy is used to examine the entire length of your colon. On the day before your procedure your doctor will prescribe a suitable oral laxative solution to clear your bowel of faeces, to allow the clearest view of the bowel. You will generally need to drink a lot of water during the preparation as you will pass large amounts of loose and sometimes watery stools. During the colonoscopy, a long, thin tube with a camera, called a colonoscope, is inserted into your bowel through your anus. You will be sedated prior to the procedure to help you to relax.

Abdomen

The part of the body that lies between the chest and the pelvis.

Anus

The opening at the end of the anal canal, between the buttocks, through which faecal matter and intestinal gas exits the body.

Bacteria

Microscopic, single-celled organisms with DNA but no definite nucleus. Bacteria are the cause of many human diseases.

Digestive system

The series of organs within the body that contribute to the digestion of food. It begins at the mouth and ends at the anus, and includes the stomach, small and large intestines as well as the pancreas, gallbladder and liver.

Enema

A procedure in which fluid or gas is injected into the rectum for cleansing, diagnostic or therapeutic purposes.

Full blood count

A blood test that examines the blood, either by using a microscope or an automated machine, to determine the number of red blood cells, white blood cells and platelets.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Inflammation

A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Laxative

Any substance that causes or encourages bowel movements.

X-ray

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Abdominal

Relating to the abdomen, the middle portion of the trunk which contains organs such as the intestines, stomach and liver.

Pancreatic

Relating to the pancreas, an organ located in the abdomen that secretes important chemicals, such as insulin, into the bloodstream and digestive enzymes into the intestines.

Types of treatment

Your doctor will be able to advise if treatment at home is suitable. Sometimes diverticulitis is a medical emergency that requires immediate hospitalisation for assessment and management.

Home care

Home care usually incorporates the following:

Liquid diet

You may be advised to have a liquid-only diet for a few days, to allow your bowel to rest and give it time to recover.

Pain-relief medications

You will most likely be given paracetamol or other pain-relief medication to help with your pain. Non-steroidal anti-inflammatories (NSAIDs) such as ibuprofen and aspirin are not recommended, as they can increase your chance of internal bleeding and upset your stomach.

Antibiotics

Antibiotics are likely to be prescribed to fight the infection in your bowel.

Hospital treatment

Hospital treatment may be necessary if you have an acute and severe case of diverticulitis with the following circumstances:

  • Your pain is too extreme to be treated with simple pain-relief medications at home;
  • You cannot take antibiotics in tablet form, or they are not effective;
  • You are severely dehydrated or in poor health;
  • You have not seen any improvement after two days of home treatment;
  • You have a weakened immune system that puts you at risk of infections, and;
  • Your care team are concerned you may develop complications.

Intravenous liquids and medications

Treatment is likely to include fluids and antibiotics, given via an intravenous drip (IV) attached to a vein in your arm. Pain-relief medications can also be given intravenously or via muscular injection. Recovery usually occurs over a few days, but can depend on the severity of your condition. 

Surgery

Surgery is usually only required in certain cases of diverticulitis. If there are certain complications, frequent episodes of infection and/or a severe infection not responding to medications, surgery may be indicated. Surgical treatment can comprise the following:

Bowel resection

Bowel resection is a type of surgery in which the affected part of your bowel is removed. You will be under general anaesthetic during the surgery, so will not feel any pain. Once the unhealthy part of your bowel is removed, your surgeon will either staple or sew the healthy parts together. You will probably be kept in hospital for 3-7 days after surgery and receive fluids via an IV drip for the first few days. Food is generally gradually reintroduced as tolerated.

Stoma surgery

Your surgeon may decide to give your bowel time to heal before reattaching it, either temporarily or permanently (rarely). This can be done by creating a special opening, called a stoma, in your abdomen. Your faecal matter passes through this opening into a special bag. You will usually undergo surgery to reattach your bowel once the bowel has healed.

Abdomen

The part of the body that lies between the chest and the pelvis.

Antibiotics

Chemical substances that kill or suppress the growth of bacteria.

Dehydrated

The state of insufficient hydration; excessive loss of water; requiring more water in order to function normally.

Immune system

The organs and cells involved in protecting the body against infection.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Intravenous drip

A small tube inserted into a vein to administer fluid.

NSAIDs

Non-steroidal anti-inflammatory drugs are commonly used to manage arthritis-related pain and inflammation and other musculoskeletal disorders. NSAIDs include aspirin and ibuprofen.

Potential complications

There are a number of potentially serious complications of diverticulitis:

  • Perforation - this is when your bowel wall ruptures, allowing its contents to escape into your abdominal cavity. This is a life-threatening situation requiring immediate surgery;
  • Abscess - this is a collection of pus that forms in an area where you have developed an infection. If the abscess bursts, it can cause blood infection (sepsis) or bowel perforation;
  • Fistula - an abnormal channel that forms between two areas of the body not supposed to be connected, such as your bowel and bladder;
  • Peritonitis - infection of the lining of your abdominal cavity requiring immediate treatment. It often happens if an abscess bursts or if a bowel perforation occurs;
  • Intestinal obstruction - a blockage of your bowel, stopping the passage of both liquids and solids;
  • Sepsis (septicaemia) - this happens when an infection spreads throughout your bloodstream, and;
  • Haemorrhage - uncontrolled bleeding, usually due to a blood vessel rupturing near your diverticula. Surgery may be required to stem the bleeding.

Abscess

A swollen area of tissue containing a build-up of pus.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Pus

A bodily fluid that is the result of an inflammatory response at an infection site. Its colour can range from whitish to yellow to green, depending on the composition. Pus is mainly composed of dead bacteria, white blood cells and cellular debris.

Abdominal

Relating to the abdomen, the middle portion of the trunk which contains organs such as the intestines, stomach and liver.

Prognosis

If you have had an episode of diverticulitis, you have a higher chance of having future episodes. Changing your diet, taking fibre supplements and leading an active lifestyle are the best ways to improve your future health. If you have further symptoms such as rectal bleeding, your doctor will advise further management based on your individual situation.

fibre

Ingredients in food that are not digestible. They pass through the digestive system relatively unchanged and help to keep the digestive system healthy.

Rectal

Relating to the rectum, the final part of the large intestine leading to the anus.

Prevention

Diverticular disease is one of the most common bowel disorders in older people in Australia and the Western world. The best way to avoid its recurrence is to get active, quit smoking and, to avoid constipation, follow a healthy diet that contains at least five portions of fruits and vegetables a day with lots of wholegrain foods and water. Taking a fibre supplement will also help you prevent constipation and reduce further pressure on your colon.

fibre

Ingredients in food that are not digestible. They pass through the digestive system relatively unchanged and help to keep the digestive system healthy.