What is Crohn's disease?
Crohn’s disease is a chronic inflammatory disease that can affect any of the gastrointestinal tract from the mouth to the anus. Most commonly however, it affects the last part of the small bowel (ileum). The colon and rectum are also commonly affected and some patients develop anal fistulas. It can also affect other parts of the body leading to skin rashes, inflammation of the joints and eyes. Some of these respond to medical treatment.
What are the symptoms of Crohn's disease?
Symptoms vary from patient to patient depending on which part of the intestine is affected and the severity. Common symptoms include:
Fatigue and anaemia
Rectal bleeding and/or mucous
Who does it affect?
Any age group can be affected but most patients are young adults between 16 and 40. It affects men and women equally and around 1 in 5 will have a family member affected with Crohn’s disease.
Crohn’s disease is often grouped with a similar condition called ulcerative colitis (UC). Together they are know as inflammatory bowel disease (IBD).
What causes Crohn's disease?
The exact cause of Crohn’s disease is not known. There is strong evidence that a combination of factors are probably involved including genetic, immunological, environmental and infectious (bacterial). It is likely that an interaction between these factors leads to IBD in a susceptible individual.
How is Crohn's disease diagnosed?
Crohn’s disease can be difficult to diagnose as it can mimic a range of conditions including appendicitis, anal abscess/fistula and irritable bowel syndrome (IBS). Often a gastroenterologist or colorectal surgeon will make the diagnosis with a combination of imaging (CT scan, MRI small bowel), endoscopy (colonoscopy, pill cam), and pathology (biopsy or surgical specimen).
How is Crohn's disease treated?
The treatment depends on the area of the gastrointestinal tract affected and the severity but is usually medical. Smoking cessation is critical. The medication options are similar to those used in UC. Medications like mesalazine seem to be less beneficial in Crohns, so generally immunomodulators such as azathioprine, 6-MP or sometimes methotrexate are used early in the disease course. When standard drug therapy is ineffective, newer biologics are now available such as infliximab and humira. These drugs are very expensive and are not subsidised on the MBS for all patients. Steroids such as prednisolone may be used in the acute phase to settle the inflammation but their side effects limit long term use.
Unlike with UC, Crohn’s disease cannot be cured by surgery because it is not possible to remove all of the bowel that can potentially be affected by Crohn’s.
What operations might I need and when?
Most patients (70-90%) will need surgery at some point. The type of surgery depends on the location and severity of disease. Emergency surgery is sometimes needed including for bowel perforation, bowel obstruction or significant bleeding. In general, the indications for surgery include:
Cancer/dysplasia. Uncommon. Usually need the entire colon removal.
Perforation. Need immediate surgery, usually resection of the diseased segment and often a stoma.
Bleeding. Most bleeding will settle but sometimes surgery is required.
Toxic megacolon. Where the inflamed bowel becomes acutely dilated.
Stricture. A narrowing of the bowel. A small bowel stricture may be treated with either stricturoplasty (a widening operation) or resection. Generally colonic strictures are treated with resection due to the high rates of recurrence and risk of cancer.
Abdominal abscess. Usually needs drainage under radiology guidance followed by surgery.
Small bowel or colon fistula, usually need surgery.
Growth retardation in children
Failure of medical treatment. Generally accepted as on-going symptoms 3-4 months after starting treatment.
Anal disease. Abscess needs drainage. Fistula usually needs a soft seton drain.
The decision for surgery is best made in consultation with both your colorectal surgeon and gastroenterologist.
Who should do my surgery?
A colorectal surgeon who has appropriate training and skills in the surgical treatment of inflammatory bowel disease, and who works closely with your gastroenterologist. In Australia, members of the CSSANZ have this expertise.
Am I likely to need more than one operation?
Around half of patients will require a second operation after their initial surgery. This can be many years after the first operation. Your gastroenterologist will likely continue to treat you with medications to prevent disease recurrence.
Should surgery be avoided at all costs?
Whilst it is true that medical management is the mainstay of treatment in Crohn’s disease, surgery is required in around 4 in 5 patients at some point. Many patients suffer unnecessarily when they have a clear indication for surgery due to the mistaken belief that surgery will not help and will lead to complications. It is true that surgery is not “curative”, but it can provide sustained relief of symptoms and improve quality of life.