rel="nofollow" href="#fb3_img_img_d4e129e0-5ba0-5260-886b-b7a7889c112c.jpg"/> Erythrocyte sedimentation rate (ESR): The ESR measures how quickly red blood cells settle at the bottom of a blood sample. If there is active inflammation, red blood cells tend to clump together, making them sink faster. A raised ESR can therefore indicate active inflammation.
C-reactive protein: A raised level of C-reactive protein indicates there is inflammation. This test is often done in conjunction with the ESR.
Ferritin: Low ferritin levels may indicate the need for iron supplements; the levels also vary when there is inflammation.
Vitamin B12 and folic acid: Because vitamin B12 is only absorbed in the end portion of the ileum, anyone who has had severe damage to (or removal of) the ileum may need regular Vitamin B12 injections. Low folic acid levels can indicate poor nutrition and perhaps poor absorption from the small intestine.
Liver function tests (LFTs): Liver function can be affected by inflammatory bowel diseases (IBDs) and also by certain medication. LFTs also measure the levels of important proteins like albumin, which can be affected by poor nutrition or absorption.
Urea and electrolytes (U&E): The levels of urea and creatinine, sodium, potassium, chloride and bicarbonate give an indication of how the kidneys are functioning. They also give clues about nutritional status – especially useful if you are being given extra fluids and salt because of severe diarrhoea.
Endomysial antibody (EMA) screening test: This test looks for special antibodies in the blood which are always present in people with coeliac disease, but which are never found in people who don’t have it.
Bone chemistry: This test measures blood calcium, phosphate and levels of alkaline phosphatase, which helps doctors see how well nourished we are. It is also used to check for bone problems – though it doesn’t give much information about the possibility of osteoporosis.
Magnesium: Levels of magnesium can become very low with severe diarrhoea and can cause muscle weakness.
Scans
Ultrasound scans: Using ultra-high frequency sound waves, these painless scans give internal pictures of the body’s organs and can help doctors detect tissue masses, abscesses and fluid. They can also show thickened or inflamed sections of the intestines. A hand-held device rather like a microphone is covered in jelly and then gently moved around the surface of the abdomen to give two-dimensional black and white pictures of our insides on a monitor. Ultrasound scans normally take about 15–20 minutes. Endo-anal ultrasound scans use a probe placed just inside the anus, and are performed when there might be a problem with the sphincter muscle structure – for example, in people suffering with faecal incontinence.
CT scan (computerized tomography): This uses an enormous round machine with a hole in the middle, through which the patient, lying on a table, slowly passes. The CT scanner takes multiple x-rays, which are like ‘slices’ of the patient. A computer then puts these together to recreate a three-dimensional image. You may have an intravenous injection of a special dye to show certain features up better, or you may swallow a contrast liquid or have it injected into the rectum. You normally have to fast for around 4 hours beforehand, and will need to stay still while the scan is performed. It can take 30–40 minutes. Newer machines are becoming much faster and advanced technology has also meant the development of spiral CT and ‘multi-slice’ CT scans, which are quicker.
PET scan (positron emission tomography): This is one of the newest medical scanning techniques. It is often used to analyse the brain and heart, but can also detect tumours. PET scanning measures the uptake by certain body tissues of molecules like oxygen or glucose that are specially labelled with a radioactive substance. This indicates how well the body tissues are functioning. Tumours, for example, have a high energy demand and labelled glucose shows up clearly in a tumour. PET scans give more information about the activity of body tissues rather than their physical form.
MRI scan (magnetic resonance imaging): MRI scans use magnetism (not x-rays) to create three-dimensional, very detailed pictures of the human body. They are very good for looking at solid objects like the bones and liver, though less good at the intestines, which are constantly moving. Patients lie on a table inside a small chamber of the scanner and although you don’t feel anything, you hear a loud series of ‘knocking’ noises. People with claustrophobia may not be comfortable or able to tolerate an MRI scan while awake. Newer ‘open’ MRI scanners may minimize this problem.
Nuclear medicine (white cell) scan: This technique can be useful for locating areas of inflammation in the intestines. A sample of blood is taken and the white cells are given a mildly radioactive ‘marker’ before being injected back into the patient. Because white cells are naturally attracted to areas of inflammation, they show up in concentration when the body is scanned using a gamma camera that picks up the radioactive marker. There are other types of nuclear medicine scan that use different radioactive isotopes.
X-rays
X-rays, perhaps one of the most common – and oldest – medical imaging techniques, give the doctor a ‘snapshot’ of the chest, abdomen or bones. In order for soft tissue such as the digestive tract to show up on the x-ray properly, a ‘contrast’ substance needs to be introduced. Contrast substances such as barium are swallowed, injected into the rectum or injected into the blood vessels.
Abdominal x-rays: Abdominal radiography normally looks at the pattern of gas (wind) in the digestive tract – this can give a lot of information about what is happening inside the abdominal cavity. It can show intestinal obstructions and also give important clues to the extent and severity of diseases like UC. It does not normally involve a contrast element.
Joint radiography: While bones aren’t digestive organs, they can be affected by IBDs. Bone x-rays can show inflammation in the spine, joints, pelvis or hips.
Bone densitometry (DEXA scan): If malnutrition has been a chronic problem, or if steroids have been taken for a significant period of time, there is always a chance that there is insufficient calcium stored in the bones – which may eventually lead to osteoporosis and bone fractures. DEXA scans check the density of bones in the lower spine and femur (thigh) bone and are often given to patients who suffer with UC or Crohn’s.
Barium meal and barium swallow: A barium meal involves swallowing
