Inflammatory Bowel Diseases

Crohn’s disease can affect any part of the gastrointestinal tract from the mouth to the anus, but is most commonly found in the last part of the small intestine (the ileum) or the colon (large intestine). Intestinal tissue may be affected in patches with normal tissue in between. Over time the inflammation caused by the Crohn’s disease can cause narrowing of the colon, ulcers (painful sores on lining of intestine) or fistulae (tunnels through the intestinal wall into another part of the gut or another organ). Other complications of Crohn’s disease include bowel obstruction, weight loss due to malabsorption, anaemia from bleeding tissue, and infections.

Ulcerative colitis is characterised by the inflammation of the colon surface lining. Although the symptoms may be similar to those seen with Crohn’s disease, the tissue inflammation is continuous, not patchy. Ulcerative colitis tends to present more frequently with bloody diarrhoea, which can lead to anaemia.

Signs and symptoms of Crohn’s disease and ulcerative colitis, are similar and overlap, often making it difficult to distinguish between the two. Symptoms usually develop gradually over time but sometimes may appear suddenly.. There may be times when the disease is active (flares), when symptoms are most noticeable, and periods of non-activity (remission), when signs and symptoms subside, sometimes for months or years at a time.

While signs and symptoms vary in severity and differ from person to person, the most common ones include:

• Abdominal cramps and pain
• Persistent diarrhoea
• Blood in the stool
• Loss of appetite and unexplained weight loss

Less common signs and symptoms may include:

• Fever
• Fatigue
• Anaemia
• Joint pain
• Skin rashes
• Failure to thrive and delayed growth in children

The diagnosis of Crohn’s disease or ulcerative colitis is based on a combination of clinical assessment, biochemical, imaging and biopsy investigations. Patient family history is also important, as first-degree relatives of patients with IBD have an increased risk of developing IBD.

Diagnosis is primarily made using faecal calprotectin followed by other non-laboratory tests. However, laboratory testing is an important tool for ruling out other causes of diarrhoea, abdominal pain and inflammation of the colon, such as bacterial infections or coeliac disease.

Calprotectin is the most abundant protein present in neutrophils, which are cells associated with inflammation. The concentration of calprotectin in faeces correlates with the level of bowel inflammation present; therefore tends to be increased in IBD, but not in IBS. A negative faecal calprotectin result supports the diagnosis of IBS. However, an elevated faecal calprotectin result only indicates the presence of gastrointestinal inflammation, and further diagnostic assessment is needed to establish the cause.

In October 2013, national guidelines recommended that faecal calprotectin testing could be used to support clinicians in differentiating IBD from IBS. Importantly, faecal calprotectin analysis may avoid the need for more invasive tests (such as endoscopy) to distinguish between these two disorders.

Laboratory Tests
Common tests that may be requested to exclude other causes include:

• Stool culture to look for bacterial infection
• Ova and parasite examination of the stool
• Clostridium difficile to detect toxin created by bacterial infection; may follow antibiotic therapy
• Stool white blood cell count (WBC)
• Screen for Coeliac disease tests

Non-Laboratory Tests
These tests are used to help diagnose and monitor IBDs. They can be used to look for specific changes in the structure and tissues of the intestinal tract and to detect blockages. Care must be taken during an acute attack or flare-up of an IBD as there is a slight chance of perforating the bowel during testing.

• Sigmoidoscopy: a slender tube is used to examine the last two feet of the colon
• Colonoscopy: a slender tube is used to examine the entire colon; it includes a light and camera and can be used to take biopsies
• Capsule endoscopy: may be used in selected patients. A small pill shaped camera is swallowed so that it travels through the digestive system. The camera records images of the digestive tract which can be viewed by the doctor
• Barium meal and follow through: after swallowing barium contrast dye, abdominal X-rays picture the small intestine
• Biopsy: tissue samples taken from the colon are assessed for inflammation and abnormal changes in cell structure

Treatment of inflammatory bowel diseases is targeted at reducing inflammation, relieving symptoms and treating complications.

Patients with Crohn’s disease or ulcerative colitis need to be regularly monitored to monitor the longer term complications of the disorder, such as malnutrition. While lifestyle changes, such as diet modification and stress reduction, may help improve a patient’s quality of life and extend a remission, they cannot prevent an IBD flare-up. Acute symptoms are treated with a variety of medicines, but many can only be given for short periods of time because of their side effects.

Current therapies include the use of anti-inflammatory drugs, immunosuppressive drugs (to control and to suppress inflammation), biologic therapies (drugs that target body chemicals that cause tissue damage), probiotics and antibiotics. Patients may require surgery at some stage, either to remove damaged sections of the intestine or to treat an obstruction or fistula.

Infliximab, an anti-TNF monoclonal antibody with strong anti-inflammatory effects, may be used in active Crohn’s disease if other treatment options have not worked.