Bones and IBD Part 2

How do doctors diagnose weak bones?

Osteoporosis is best diagnosed by measuring bone density or BMD using a DEXA (dual energy x-ray absorptiometry) scanning machine. This uses low dose xrays to take a scan of your hip or spine. It is a simple, painless test which takes about 20 minutes. 

Smaller and more portable peripheral DEXA (pDEXA) scanners and ultrasound scanners can be used to measure the bone density in areas other than the hip or spine – they may be used to scan your finger, heel or forearm. These scans can then be used to decide whether you need treatment, or whether you should go on to have a hip or spine DEXA scan. DEXA hip scans remain the preferred way to confirm a diagnosis of osteoporosis. 


Conventional x-rays are of little help, unless fractures have already occurred. Biochemical tests, including blood vitamin D levels, can be helpful in the diagnosis of osteomalacia. Avascular necrosis of the hips can be diagnosed by an x-ray of the hip joint, or by an MRI scan. MRI scanners produce computer images of internal organs and the bones using strong magnets and radio waves rather than x-rays.

Will I be offered these tests?

You are most likely to be offered a bone scan if you not only have IBD, but are also in a higher risk group for other reasons: for example, if you are a postmenopausal woman, have been through an early menopause, or have been taking steroids. Some doctors may measure your bone density even if you do not come into the above categories. 

The World Health Organisation has recently developed a new way of assessing fracture risk, called FRAX. This takes into account a number of clinical factors, including age and steroid use. It can be used to calculate how likely it is for you to have a fracture in the next ten years, without even having to take a bone density measurement. Those shown by FRAX to be at intermediate or high risk can then be referred for a bone density scan and for treatment if this is needed. 

Will I be offered treatment?

The results from a DEXA scan are used to work out a bone density ‘score’ by comparing your bone density to that of the general population. Treatment recommendations then depend on this score and on your other risk factors, for example, whether you have used steroids or have had fractures in the past. 

What treatments are there?

Treatments for low bone density and osteoporosis are aimed at strengthening existing bones, preventing further bone loss and reducing the risk of fractures. Making sure that you are taking enough calcium and vitamin D is an important first step, and supplements may be recommended. If you have malabsorption, as sometimes happens with Crohn’s Disease, you may be prescribed additional high dose vitamin D as tablets or by injection.

Bisphosphonate drugs, such as risedronate, alendronate, and ibandronic acid, have been shown to reduce bone loss and are commonly used to treat osteoporosis. Research shows that such bisphosphonates are also effective in people with IBD, and can be used to prevent and treat bone loss linked to steroids.


Bisphosphonates usually come in tablet form, although some bisphosphonates such as ibandronate can be given as an intravenous (into a vein) injection. If you are prescribed oral (by mouth) bisphosphonates it is important to take the tablets exactly as directed, for example upright while sitting or standing, with plenty of water, to reduce the risk of irritating the lining of the oesophagus. 

Research in 2010 suggested a possible link between oesophageal cancer and oral bisphosphonates, but more recent reports do not confirm this. Bisphosphonates are not recommended for women who are pregnant, or might become pregnant in the future, or who are breastfeeding.

There are other drugs for osteoporosis that your doctor may prescribe, such as raloxifene, strontium ranelate or calcitonin, but not all of these have been tested for people with IBD.

Avascular necrosis of the hip is a rare but serious condition that often needs surgical treatment. If you develop hip pain during steroid therapy, report it to your doctor. With effective treatment, improved bone density can usually be confirmed with follow-up DEXA scans. However, as bone strengthening is a gradual process, it will not show up immediately. 


In Part 3: How to Prevent Bone Loss