CONSTIPATION

Symptoms of constipation

The symptoms of constipation include:

• needing to open the bowels less often than usual
• hard, dry stools that may be painful to pass
• straining to pass the motion
• having to sit on the toilet for much longer than usual
• the sensation afterwards that the bowel hasn’t fully emptied
• bloated abdomen
• abdominal cramps.

In some cases, constipation is caused by more serious illnesses and events, including tumours and systemic diseases.

Medical causes of constipation

Constipation is sometimes symptomatic of underlying medical problems, such as:

• Disordered defecation – this condition is an important cause of chronic constipation and is caused by insufficient forward contractions of the lower bowel (anorectum), or by increased resistance in the lower bowel. Straining is a very common symptom and individuals with disordered defecation may need to push on or trigger the anal canal to generate defecation.
• Slow transit – some people naturally pass motions less often than most people. It seems their bowel ‘pacemaker’ may be less active. These individuals are more likely to become constipated with minor changes in their routine.
• Irritable bowel syndrome – characterised by abdominal pain, bloating, and either constipation or diarrhoea or alternating constipation and diarrhoea. People with irritable bowel syndrome may have features of slow transit, disordered defecation, or both.
• Anal fissure – a tear in the lining of the anus (anal mucosa). The person may resist going to the toilet for fear of pain.
• Obstruction – the rectum or anus may be partially obstructed by, for example, haemorrhoids (piles) or a rectal prolapse.
• Rectocele – the rectum pushes through the weakened rear wall of the vagina when the woman bears down or strains.
• Hernia – an abdominal hernia can reduce intra-abdominal pressure, which makes it more difficult to pass a motion.
• Abdominal or gynaecological surgery – a combination of change in routine, strange surroundings, post-operative pain and codeine-containing analgesics is a potent cause of constipation and often needs preventive care.
• Problems of the endocrine system – such as hypothyroidism, diabetes or hypopituitarism.
• Tumour – pain while trying to pass a stool could be a symptom of rectal cancer.
• Diseases of the central nervous system – such as multiple sclerosis, Parkinson’s disease or stroke are associated with an increased susceptibility to constipation.

Complications of chronic constipation

Some of the complications of chronic constipation include:

• Faecal impaction – the lower bowel and rectum become so packed with faeces that the muscles of the bowels can’t push any of it out.
• Stercoral ulcer – the presence of impacted stool can erode the lining of the lower bowel. These ulcers can cause significant bleeding or bowel perforation.
• Faecal incontinence – an overfull bowel can result in involuntary ‘dribbling’ of diarrhoea.
• Haemorrhoids – constant straining to open the bowel can damage the blood vessels of the rectum.
• Rectal prolapse – the constant straining pushes a section of rectal lining out of the anus.
• Urinary incontinence – the constant straining weakens pelvic floor muscles. This makes the involuntary passing of urine more likely, especially when coughing, laughing or sneezing.

Diagnosis of constipation

The underlying reason for the constipation must be found. Diagnosis may include:

• a careful medical history, to determine the type of disorder
• detailed questioning about medications, diet, exercise and lifestyle habits
• physical examination, including an examination of the anal canal and rectum
• a trial of simple laxatives is usually done, as the outcome of this helps with accurate diagnosis of the cause
• referral to a specialist in disorders of defecation, who may perform simple tests of anorectal function, or anorectal manometry (pressure measurements of the rectum and anus)
• colonoscopy in those with alarm symptoms or aged over 50 with new onset of constipation.

Treatment for constipation

Treatment depends on the cause, but could include:

• Stopping or changing medications – that can cause constipation.
• Removal of the impacted faeces – which may involve enemas, stool softeners and a short-term course of laxatives.
• Dietary changes – such as increasing the amount of fibre in the daily diet. Dietitians generally recommend about 30g of fibre every day. Good sources of fibre include wholegrain cereals, fruits, vegetables and legumes. The intake of foods such as milk, cheese, white rice, white flour and red meat should be restricted, because they tend to contribute to constipation.
• More fluids – liquids help to plump out faeces. However, it is important to restrict the intake of diuretic drinks such as tea, coffee and alcohol.
• Fibre supplements – these may be helpful if the person is reluctant or unable to include more wholegrain foods, fresh fruits or vegetables in their daily diet. As fibre supplements can aggravate or cause constipation, always check with your doctor or dietitian when using them.
• Exercise – one of the many benefits of regular exercise is improved bowel motility. Ideally, exercise should be taken every day for about 30 minutes. People with a condition that affects mobility need to be as active as possible each day, as every little bit of regular exercise helps.
• Treatment for underlying disorder – such as surgery to repair an abdominal hernia, hormone replacement therapy for hypothyroidism, or anaesthetic cream and sitz (salt water) baths for an anal fissure.
• Laxatives – there are 2 main types: bulk forming and osmotic agents that increase the water content of the stool. Agents that increase the water content may interfere with the absorption of water from the bowel, or swell or bulk up the stool with fluid. Chronic constipation that has not responded to a trial of fibre supplementation can be safely treated long term with laxatives and avoid further medical interventions. There is little evidence that chronic use of laxatives at appropriate doses will lead to a ‘lazy’ or ‘twisted’ bowel.