Problems with emptying the bladder
Broadly speaking, problems with emptying the bladder (or ‘voiding’) can be divided into two groups. If the bladder muscle is weak or does not contract as it should, then the bladder will not empty properly. Or if the bladder neck cannot relax or is scarred, it will be difficult for the bladder muscle to force urine past it. In both cases the bladder may not empty completely. These processes can occur separately or together.
A common complaint that indicates a difficulty in emptying the bladder in women is recurrent cystitis, because the problem reduces the normal protective mechanisms against bladder infection. Bacteria are normally washed away from the bladder and the area outside the urethra during voiding. If the bladder is not emptying properly, the bacteria will stay there for longer and be more likely to cause infection.
This is the symptom of wanting to void and the delay between trying to start and voiding. In an extreme form it leads to strangury, which is pain associated with trying to void. This is more commonly associated with prostatism, a male disorder.
Symptoms of voiding difficulties
- Recurrent infections
- Urgency & frequency
- Overflow (dribble) incontinence
- Bladder pain
Urgency and frequency
If the bladder does not empty properly it reduces the available space, which may then result in increased frequency of micturition and in nocturia (getting up at night more than normal to pass urine).
Urgency may also be a problem (see Glossary).
Retention is a condition where the bladder cannot empty. If this occurs as a sudden event it is usually very painful and requires immediate action to prevent damage to the bladder as a result of prolonged over-filling.
Chronic retention can also occur, which is usually relatively painless. Retention occurs because the bladder outlet becomes obstructed – for example, as the result of a fibroid pressing on the urethra – or the bladder is unable to create enough muscle power to enable emptying.
The first part of treatment is to drain the bladder using a catheter. Once that is done, the doctor may then arrange tests to determine the cause, for example, a mass pressing on the bladder. In this case, the tests include a blood test to check that the kidneys have not been damaged by the pressure exerted on them by the bladder, and an ultrasound scan. Urodynamics may also be used.
Overflow (dribble) incontinence
When the bladder is unable to empty, the pressure inside it will eventually build up so much that urine leaks ‘off the top’. This is known as overflow incontinence and is non-acute retention. There may be an almost continuous leakage of urine (dribble incontinence).
This sort of problem is mostly seen in men with prostate problems but can occur in women, particularly if there is pressure on the bladder from a large uterine fibroid. Overflow incontinence can also occur in association with other medical problems such as multiple sclerosis where bladder coordination is lost. In these cases, the bladder contracts to empty but at the same time the urethral sphincter (the ring of muscles controlling the opening of the bladder) contracts to stop the bladder emptying.
Dribble incontinence may also be caused by fistulae.
Bladder pain caused by voiding difficulties is normally an intense desire to empty the bladder, which is called urgency. The pain is normally ‘suprapubic’, that is, just above the pelvic bone. Infections are often associated with this intense urgency; classically, however, infections also cause a burning pain during passing of urine. In severe cases there may even be a dull ache left after voiding.
Causes of voiding difficulties
Medications such as antidepressants can suppress the bladder’s ability to contract. If the bladder function is normally relatively weak, this can tip the balance between being able to empty and going into retention.
Damage to the nerves supplying the bladder can alter the bladder muscle’s ability to contract; hence a chronic or severe back problem (for example, a slipped disc) can trigger off difficulties.
Causes of urinary retention & voiding difficulties
- Nerve injury/ neurological problems
- Epidural anaesthetic
- Fibroids/ pelvic masses
- Narrowing of the urethra
- Weak detrussor muscle
- Urinary tract infections
Urinary retention can commonly result from childbirth, particularly after an epidural anaesthetic, which will decrease bladder nerve function. Women who have had an epidural should have an indwelling catheter to protect the bladder until normal sensation returns (about 12 hours).
There is also an increased risk after a forceps delivery, or when there is marked trauma to the perineum and vagina that may make passing urine painful, and hence the woman avoids voiding and eventually becomes unable to do so.
Fibroids are a common gynaecological condition that occasionally cause difficulties in emptying the bladder. Fibroids are benign tumours growing in the uterus. If they cause an external obstruction to the bladder neck, it becomes increasingly difficult to empty the bladder.
As the fibroids grow, the problem increases until the woman goes into retention. Any other lump or mass in the pelvis (constipation, for example) can cause similar problems.
One of the most common causes of temporary voiding difficulties is pelvic surgery, and continence surgery in particular. When the bladder neck is lifted to reposition it, there is always an element of obstruction. If the pressure of the contraction of the bladder muscle cannot overcome this, then there will be difficulties in emptying the bladder.
Most women who have had a colposuspension, for example, will notice that they void at a slower rate after surgery.
Postoperative voiding difficulties can be divided into short-term and long-term problems. Around 20 per cent of women have some minor degree of voiding dysfunction that will settle with careful catheter management. Of these around one per cent have long-term problems that require long-term treatment.
The most successful way to manage the problem is self-catheterisation, which allows the woman to control her symptoms and gives her freedom to lead a normal life (see later).
Strictures to the urethra
Stricture or narrowing of the urethra is now relatively uncommon in women. It can occur if trauma or an infection damages the lining of the urethra, which then heals leaving scarring. Strictures cause voiding difficulties by reducing the size of the urethra and thereby creating outflow obstruction.
Urethral strictures will require an operation either to dilate or to cut the narrowed area, but need to be carefully assessed before treatment to check that there are no other problems and ensure that treatment will not damage the urethra further. Strictures often recur and sometimes require repeated treatment.
Prolapse can cause problems with bladder emptying by kinking and therefore obstructing the urethra; this is just like kinking a garden hose to stop water flowing out of the end. Correction of the prolapse then restores the bladder neck to its normal position to allow normal voiding. Often prolapse and incontinence coexist because the damage that causes prolapse also leads to stress incontinence.
Weak detrusor muscle
The detrusor muscle gets weaker with age and contracts less efficiently. The bladder wall also becomes stiffer. As a result the bladder functions less well. These are normal effects of ageing and are the reason that it takes longer for elderly people to empty their bladders, as well as needing the toilet more often.
Occasionally, the nerves to the bladder stop working properly, which stops the detrusor muscle from contracting properly. Nerve damage to the bladder occurs after urinary retention or as a result of nerve damage from diabetes, multiple sclerosis or a stroke. This may in itself not always lead to a problem because part of voiding is relaxation of the pelvic floor; this may be enough in its own right to allow emptying. Usually, however, women require active force to empty their bladders.
Voiding difficulties require thorough investigation with urodynamics (see earlier). If there is the symptom of loin pain or there have been serious kidney infections, tests will be performed to check that urine does not flow the wrong way up the ureter (from the bladder to the kidneys). In addition, a test to check on the pressure in the urethra may be performed – called a urethral pressure profile.
If there is any doubt or there is a history of infections, a cystoscopy may be performed. This allows a doctor to inspect the inside of the bladder through a ‘telescope’, which is usually done under a general anaesthetic, and also allows small biopsy samples to be taken from the bladder for analysis.
Often mild degrees of difficulty can be managed with simple advice. When sitting on the toilet, make sure that your legs are apart rather than having your knees together. Leaning forwards or even standing slightly may alter the angle of the bladder neck enough to allow better emptying. Waiting for two minutes after the initial void and trying again may help. This is known as the double void technique.
More severe symptoms may require actual treatment. There are three approaches to the treatment of voiding difficulties:
- Try to increase the force of the bladder contractions. This can be achieved in some cases using bethanechol, which stimulates the nerve fibres controlling the contraction of the bladder muscle. This may be effective if there are no signs of obstruction at the bladder neck or urethra.
- Try to reduce outflow obstruction. This method would be used if there was a specific site of obstruction in the urethra such as a stricture, or narrowing, demonstrated during investigation as mentioned above.
- Third, and probably most commonly, catheters are used. They can either be used occasionally or remain in place long term.
Occasional self-catheterisation when properly taught in a healthy individual with normal dexterity is the best option. It gives freedom to control bladder symptoms with no more inconvenience than having to change a tampon.
The use of catheters
A catheter is a soft, flexible tube, thinner than a pencil, with a rounded end. When passed up the urethra into the bladder, it allows all the urine to flow out without any muscular effort.
Although initially the thought of having to catheterise is upsetting to most women, when they have learnt the technique and are confident, they find it far easier than expected. The technique requires a basic understanding of pelvic anatomy and being taught how to identify the urethra.
Initially a mirror is helpful for this, but with time most women manage without. With practice inserting a catheter through the urethra is not normally painful.
The number of times that you might need to catheterise depends on how your bladder functions.
- Difficulties emptying the bladder may cause a variety of symptoms
- They can be caused by drugs, nerve damage, childbirth, fibroids or pelvic surgery
- Simple advice may be sufficient to deal with mild cases
- Self-catheterisation may be an effective way of managing the problem