What is Crohn’s disease?
Crohn’s disease is an inflammatory bowel disease that causes full-thickness inflammation of the bowel wall and may involve any part of the digestive tract from the mouth to the anus. Most frequently the ileum (the lower part of the small bowel) is involved but sometimes only the large bowel may be affected (or both can be are involved in segments or at times throughout).
How common is Crohn’s disease?
Crohn’s disease affects males and females at a rate of 5 in 100,000 people. Occasionally it can affect more than one member of a family. Both adults and children may have Crohn’s disease, but there are peaks of incidence around 25 and 65 years of age.
What causes Crohn’s disease?
The cause is unknown, but recent research suggests it is may be an infective process.
Symptoms
Symptoms of Crohn’s disease may include:
- abdominal pain; diarrhoea;
- malaise and fever;
- the passage of blood and mucous;
The abdominal pain may be localised, particularly in the lower right side of the abdomen, and it can mimic appendicitis.
Bleeding, when present, may be mixed with the stool and is often unobtrusive and can lead to anaemia and iron deficiency.
Painful mouth ulcers, lethargy and weight loss may also occur.
How does Crohn’s disease affect the bowel?
Patchy inflammation involving the lining of the bowel will extend through the full thickness of the bowel wall. The inflammation causes ulceration, scarring, and narrowing of the bowel, resulting in bowel symptoms and a general feeling of malaise. Bleeding from the bowel may cause anaemia.
Abscesses can form adjacent to the inflamed bowel and burst into other organs, causing an abnormal track between the organs (fistula).
Bowel ulceration causes diarrhoea, often with blood and mucous, and can lead to malnutrition.
Narrowing of the bowel causes cramping pain due to the incomplete blockage. Should the anus be involved, fistulae, fissures, watery mucous discharge, and some bleeding may occur.
Other organs may be involved, causing joint and eye inflammations and skin rashes.
Diagnosis
The diagnosis of Crohn’s disease is sometimes delayed as the same symptoms can occur with other diseases. It is usually necessary to exclude diseases such as bowel infections or irritable bowel syndrome.
Blood tests are useful when looking for anaemia; they measure the severity of inflammation. They can also detect vitamin or mineral deficiencies. A faecal specimen may be required to exclude infection.
Most people require an examination of part of the bowel. This can be a colonoscopy, gastroscopy or sigmoidoscopy. X-ray, CT scan, and barium enemas are sometimes helpful.
There is no single test that will reliably diagnose all cases, and many people require a number of tests.
Treatments
There is no “cure” for Crohn’s disease. Medication may be helpful in controlling inflammation and some of the symptoms. The main drugs prescribed are Salazopyrin and Prednisone. Anti-diarrhoeal medications, iron and nutritional supplements are used. New medications are constantly being developed.
Localised complications of Crohn’s disease can cause troublesome symptoms that do not respond to medication and surgery may be necessary.
Any surgical procedure will be tailored to your specific problem. Most patients do not need surgery and, when required, the extent of surgery needed varies considerably.
Prognosis
Most people with Crohn’s disease have normal length of life.
Ulcerative colitis is inflammation of the lining (mucosa) of the large intestine or colon.
What is the cause of ulcerative colitis?
The cause is unknown. It does not appear to be contagious or hereditary. It is rare for more than one family member to have the condition. Diet is not a contributing factor. It may follow acute diarrhoea.
How common is ulcerative colitis?
Ulcerative colitis is a rare disease, affecting approximately 5 in 100,000 people. Males and females are equally affected.
Ulcerative colitis and the bowel?
Only the large bowel is involved. Inflammation may start at the rectum and extend to the beginning of the large bowel (caecum). If the caecum is involved it is called pancolitis. If only the rectum is involved, it is proctitis. Ulcerative colitis is comparable to a “burn” of the inner lining of the bowel resulting in inflammation and shallow ulceration. This causes diarrhoea, bleeding and mucous. Given time, a patient may become anaemic.
Other problems
Occasionally liver disease, eye inflammation, arthritis, and skin lesions may occur. Ulcerative colitis is a pre-malignant disease, and the incidence of colon cancer progressively increases with the duration of the disease.
Symptoms
Symptoms are many and varied. They can include episodic or continuous diarrhoea with blood and mucus, urgency to defaecate, with cramping lower abdominal pains. Symptoms can be mild or severe, with multiple bowel actions each day. Patients can feel completely normal or become very ill. Episodes can be life-threatening. The illness may be continuous or relapse.
Diagnosis
Diagnosis is based on the clinical picture and the appearance of the large bowel mucosa at colonoscopy. Biopsies are taken. In the earliest stages of the disease it is sometimes confused with other conditions. There are no diagnostic blood tests.
Treatments
Medications can be very effective. Anti-inflammatories are necessary either in the form of local rectal preparations or tablets. Sometimes immune-suppressants are needed. Iron tablets, anti-diarrhoeals and good nutrition are all helpful. There is no known cure for ulcerative colitis other than surgical removal of the large bowel. Biopsies looking for potential malignant change are usually undertaken at appropriate intervals in patients who have longstanding disease.
Surgery
Surgery may be needed when medical treatment can no longer control the symptoms, and may be used in to prevent complications such as haemorrhage, acute toxic colitis and cancer. If surgery is indicated, the aim will be to remove all the large bowel, and this will be done in one or more procedures.
Following a total colectomy you may have a permanent ileostomy (bag at the end of the small bowel). However, many patients are suitable to be considered for a restorative operation involving the construction of an internal “pouch” (made from the patient’s small intestine to act as a new storage pouch and eliminate the need for a stoma (abdominal bag). In this way, the anal sphincter muscles are preserved to maintain continence. This operation is not suitable for all patients and is more complex than a permanent ileostomy. It does result in a variable number of bowel motions in a 24 hour period. If cancer is involved, other surgical intervention may be recommended.
Prognosis
Removal of the diseased bowel removes the risk of cancer. Life expectancy should be normal.