Family doctor

OVERVIEW

Ulcerative colitis is a chronic relapsing condition where the large intestine becomes inflammed. It occurs at any age and in either sex. Blood tests and stool samples help diagnosis, but the key test is internal examination of the bowel, and biopsy. The benefits and risks of treatment versus non-treatment need careful consideration. Treatment may include drugs or surgery. Studies of new treatments indicate future management of ulcerative colitis can achieve cure, not just control.

What is ulcerative colitis?

Inflammatory bowel diseases (IBDs) are a group of chronic disorders with relapsing inflammation of the small and/or large intestine. There are two major members of this group:

• ulcerative colitis - affecting only the large intestine and involving only the inner lining of the bowel
• Crohn's disease - can affect the whole of the gastrointestinal tract from the mouth to the anus and involves the full thickness of the bowel.

The inflammation of ulcerative colitis may be confined to the distal (end)part of the bowel when it is referred to as ulcerative proctitis, or it may extend to involve the whole of the large bowel as ulcerative colitis.

Ulcerative colitis is a chronic relapsing condition. Once the disease is established it is considered to be a lifelong illness. Patients have variable periods of remission and a few have very long remissions but very few can ever be described as cured, unless the large bowel has been surgically removed.

A number of complications can occur including perforation of the bowel; cancer of the bowel; haemorrhage; or extra-intestinal disorders such as skin disorders, eye diseases,a and arthritis. These complications are increasingly uncommon with modern management.

What causes ulcerative colitis?

A number of risk factors have been identified but no single cause defined. There may be no one cause, but a number of different factors leading to local damage to the lining of the bowel sets up a chronic stereotype inflammatory response. Although some still believe ulcerative colitis is caused by infection, this is no longer a commonly well supported theory.

There is clear familial risk of developing ulcerative colitis. If both parents have the disease, the risk of developing inflammatory bowel disease is high. If one identical twin develops the disease, the other has about a 50% chance of developing either ulcerative colitis or Crohn's.

It is commonly accepted that environmental factors are important. Geographic factors have an effect - the same racial groups in different geographic locations have different incidences. Interestingly, persons with ulcerative colitis tend to be non-smokers and some smokers with colitis relapse if they stop smoking. There is no known explanation for this.

The incidence (number of new cases diagnosed per year) is highest in white populations and low in black and Polynesian races. The incidence is probably steady or increasing very slowly, unlike Crohn's disease which is steadily increasing. The incidence in New Zealand is thought to be greater than 1 in 10,000. The prevelance (number of active cases being managed at any one time) in New Zealand has not been calculated but is probably between 4-8 per 10,000.

What are the symptoms of ulcerative colitis?

the common symptoms of ulcerative colitis are:

• diarrhoea
• bleeding from the bowel
• passage of mucus (slime) from the bowel
• abdominal discomfort.

These occur with relapse and remission. It is common for these symptoms, in the early relapses, to be mild and of short duration, but with gradually increasing severity with subsequent exacerbation. The severity of the symptoms relate to the extent of the inflammatory involvement. When the involvement is confined to the rectum, diarrhoea may be replaced by constipation along with bleeding and mucus.

Fever, exhaustion and loss of appetite may occur in more severe disease.

How is ulcerative colitis diagnosed?

Ulcerative colitis may be seen at any age and in either sex. Most commonly cases first present in early adult years but cases occurring for the first time in ages over 65 years are not uncommon.

The characteristic history of a clinical illness together with a focussed physical examination are helpful when diagnosing ulcerative colitis. This information, followed by blood tests, bacteriological culture of faeces and visual examination of the bowel with biopsy, confirm the diagnosis.

While blood and stool tests are important to exclude other causes of similar symptoms, the key test is a visual examination with biopsy of the bowel. Visualisation is achieved either with a rigid tube (sigmoidoscopy) showing the lower 20 cms of bowel, or by flexible tube (colonoscopy) allowing the whole length of the bowel to be examined. Small pieces of bowel lining (biopsies) are painlessly taken for detailed examination under the microscope.

Another option is x-ray examination of the bowel to show the extent and severity of the disease. Colonoscopy has reduced the need for x-rays but these still have a place particularly when colonoscopic facilities are less readily available.

How is ulcerative colitis treated?

There is no truly risk-free treatment, and the benefits and risks of treatment versus non-treatment must be weighed up.

The goals of early treatment are to correct nutritional deficiencies; control inflammation; and relieve abdominal pain, diarrhoea and bleeding. The goals of longer term treatment are to reduce the risk of relapse; avoid complications; and provide the patient with highest quality of life.

There are two groups of drugs:

• Salazopyrine, known as specific drugs - to reduce inflammation.
• Corticosteroids, known as nonspecific drugs - to reduce symptoms.

Salazopyrine (sulphasalazine) often lessens inflammation. The significant active component of salazopyrine has been modified by biotechnology to release active ingredients at the site of inflammation. Salazopyrine drugs include dipentum, pentasa and asacol.

Corticosteroids, including prednisone, prednisolone and ACTH, are used to treat moderate or severe attacks. They are very effective for reducing inflammation and swelling of the bowel. The dose is customised to the severity of the attack and the patient's physical status. While these drugs can be given intravenously during more severe attacks, they are most common given orally or rectally. Side effects include rounding or mooning of the face, facial hair growth, fluid retention and ankle swelling, bruising and acne.

More severe cases may require antibiotics or drugs to act through the body's immune system, including azathioprine, 6-mercatoprine, clyclosporine.

Is a special diet required for ulcerative colitis?

There is no special diet appropriate for ulcerative colitis. Most patients do not require a restricted diet, however when the disease is very active and during acute phases, a bland diet low in fat, fibre and stimulating food is better tolerated.

Every effort should be made to have a diet including each of the four main food groups - vegetables and fruits; breads and cereals; milks and dairy products; and protein foods. A good selection ensures adequate intake of carbohydrate, protein and fat together with vitamins, minerals and phytochemicals needed to maintain good health. In exceptional circumstances patients may benefit from intravenous feeding.

When nutritional deficiencies occur, management by temporary supplementation is appropriate. Common supplements needed include iron, zinc, calcium, vitamin B12 and folate. Large doses of vitamins are not effective and even cause harmful side effects. A few patients lack the enzyme to break down milk sugar (lactose) and in these cases a reduced milk product should be substituted.

Does surgery have a place in the management of ulcerative colitis?

Ulcerative colitis can be cured by surgery. Emergency surgery may be life saving in a very severe acute attack, for instance if the bowel has perforated or if major haemorrhage occurs. Planned surgery may be needed if medical treatment fails, to cure the disease.

There are several operations available but none are perfect. The two important operations are:

• proctocolectomy with ileostomy
• proctocolectomy with an ileo-anal pouch

Proctocolectomy entails removal of the whole of the large bowel. From here the two options are to provide an opening of the bowel onto the abdominal wall (ileostomy); or to reconstruct a reservoir from the lower end of the small bowel and reconstitute an opening at the anus using the valular muscles of the anus to give control of bowel emptying (ileo-anal pouch).

The ileo-anal pouch is a two-stage operation and is becoming the favoured procedure under ideal conditions. Usually a reasonable bowel control is obtained, although some patients develop an inflammation of the pouch (pouchitis) that can be troublesome. Usually a longer period of adjustment is needed for this procedure than the ileostomy, but the long-term outcome is better for most patients.

Are there cancer risks with ulcerative colitis?

The risk of cancer of the colon is dependent on the extent and severity of the disease; the age when the disease became apparent; and duration from first symptoms.

For patients at the extreme of these factors, the risk of cancer rises after approximately 10 years. Those in this high risk group should be under regular surveillance by colonoscopy from between 6-10 years from first diagnosis of the disease. By taking biopsies, the colonoscopist is able to identify changes in the structure of the lining preceding cancer development and warn of increasing risk.

Patients with the inflammation confined to the rectum have risk little different from the unaffected population and do not need a rigid surveillance programme.

Between these two extremes are the main body of ulcerative colitis patients. Judgment is needed to ensure good medical practice, safeguarding the patient without raising undue anxiety.

What does future research hold for ulcerative colitis?

Ulcerative colitis is subject to intensive research. This has lead to better understanding of the process of the disease. New treatments are under extensive testing and study, including immunomodulatory therapy, cytokine receptor modulators, and variety of products from rapidly advancing biotechnology.

There is every reason to be optimistic that management of ulcerative colitis can achieve cure, not just control.