There's a form of cystitis that doesn't respond to the usual treatment, but not many people know about it, says Barbara Lantin

Imagine having to nip to the loo to urinate every 30 minutes and then spending nights constantly on 'loo-watch.' And even when you have gone, the urge to urinate quickly returns, sometimes accompanied by pain.

This is what life is like for sufferers of interstitial cystitis (IC), a condition that can intrude upon every area of life, making jobs and relationships difficult to manage. 'Many IC sufferers find that their life revolves around knowing where the nearest toilet is,' says Anthony Walker, chief executive of the Interstitial Cystitis Support Group. 'They also suffer from insomnia, depression and excessive fatigue.'

But what is it?
Interstitial means 'inside the tissue' and is a chronic inflammation of the bladder thought to affect around 400,000 people in the UK, most of them women. It shares many symptoms with common or bacterial cystitis. The main difference is that sufferers from bacterial cystitis - a urinary tract infection - usually experience acute pain on urinating, whereas those with IC find passing water brings temporary relief. It is when the bladder refills that the discomfort starts again.

The two conditions are often confused by GPs, with the result that it can take six years to get a diagnosis. IC is not caused by bacteria and its symptoms are therefore not relieved by antibiotics, which is the usual treatment for bacterial cystitis.

What causes it?
The causes of IC are not fully understood, though there may be a genetic element. The first attack is sometimes triggered by an abdominal 'insult' such as a hysterectomy, a Caesarean section or sterilisation. Some people find that the symptoms are worse after sexual intercourse and before their period.

Patients who experience the symptoms of cystitis but show no sign of a bacterial infection should ask to see a urologist. There is anecdotal evidence to suggest that the earlier the condition is treated, the better it responds - presumably because less damage has been done to the bladder.

Reaching a definitive diagnosis requires a bladder biopsy and an ultrasound. A cystoscopy, which involves examination of the inside of the bladder, is also used - around 70 per cent of IC patients have abnormalities in their bladder wall.

How is it treated?
There is a wide range of treatments available and patients may have to try several before they find one that brings relief. Anti-inflammatory drugs, antispasmodics, antihistamines and muscle relaxants are all used, and some people find certain antidepressant drugs, such as amitriptyline, seem to relieve pain. Others have found benefit from a TENS device.

Several treatments work directly on the bladder lining - such as elmiron tablets - or dimethyl sulfoxide (DMSO ) and cystitat, which are introduced into the bladder by catheter. Early studies of the neurotoxin capsaicin suggest that it may also be helpful in relieving pain when injected into the bladder.

Heal yourself
It is a good idea to keep a food diary so you can see whether symptoms are connected to diet. 'Some people find that acidic foods such as tomatoes or fruit and fruit juices make their symptoms worse,' says Mr Walker. 'Some sufferers can drink alcohol, but others cannot.'

Cranberry juice, often recommended for bacterial cystitis, is likely to make the urine more acidic and cause discomfort in IC sufferers.

Complementary therapies - notably reflexology, acupuncture and aromatherapy - have been found to be helpful. The Interstitial Cystitis Support Group is a mine of information, and can be found at www.interstitialcystitis.co.uk.