Constipation

What is constipation?

Constipation is one of the most commonly reported digestive complaints in Australia, affecting as many as one in five adults at some point in their lives. Despite how widespread it is, relatively few people seek medical attention for it, which means many are managing symptoms alone, often without the support or information they need.

The term “constipation” describes difficulty emptying the bowels as often or as completely as feels normal. It is worth noting that bowel habits vary considerably between individuals. A normal frequency can range from several movements each day to as few as three per week. It is the change from what is usual for a person, combined with symptoms such as straining or discomfort, that tends to indicate a problem.

Constipation becomes more prevalent with age. It is particularly common in adults over 65, and it also affects children. One in ten will visit a doctor for this issue, which accounts for three to five per cent of all paediatric consultations.

What causes constipation?

There is rarely a single cause. Constipation can arise from a combination of factors, and understanding these is an important first step in managing the condition effectively.

Lifestyle is often a significant contributor. Insufficient dietary fibre, low fluid intake, and limited physical activity can all impede normal bowel function. Beyond lifestyle, age related changes in gut motility play a role, as do functional gut disorders such as irritable bowel syndrome (IBS) or slow transit constipation, conditions where the bowel moves contents through more slowly than it should. Pelvic floor dysfunction can also affect the ability to pass a bowel motion comfortably.

Certain medications are a well recognised cause, particularly opioid pain relief and some antidepressants. Hormonal changes, including those that occur during pregnancy, in the lead up to menstruation, or with thyroid conditions, can also disrupt bowel regularity. In some cases, neurological conditions such as Parkinson’s disease or stroke affect the nerves that control gut movement. In a small number of infants and young children, cow’s milk allergy has been identified as a cause of significant constipation.

The majority of patients, especially those who have experienced symptoms for a number of years, have what is termed functional constipation, which does not reflect any serious underlying disease. This condition has a tendency to run in families, with close to a third of patients having at least one other family member with similar bowel concerns.

However, certain symptoms warrant prompt medical assessment. A recent and unexplained change in bowel habits, unintentional weight loss, persistent or heavy rectal bleeding, or significant abdominal pain may indicate an underlying cause that requires further investigation.

What are the symptoms of constipation?

The most recognisable symptom is a reduced frequency of bowel movements, typically fewer than three per week. Many people also experience straining during a bowel motion, the passage of hard or dry stools, or a persistent sensation of incomplete emptying or internal blockage. In more severe cases, some individuals find they need to use manual assistance to achieve a bowel movement.

When stools are particularly hard and dry, they can cause a small tear in the lining of the anal canal, a condition known as an anal fissure. This may result in localised pain and stinging, along with a small amount of bright red bleeding visible on toilet tissue or in the toilet bowl.

In children and older adults who have experienced long standing constipation, the rectum, which is the lower portion of the large bowel, can become stretched over time. When this occurs, the normal sensation of needing to pass a motion may diminish, which can lead to an overflow of watery stool and unintentional soiling. This presentation, while distressing, is a recognised consequence of prolonged untreated constipation and should prompt a medical review.

Can lifestyle changes help?

For many people, adjusting daily habits provides meaningful relief. A diet that includes adequate fibre and fluid, combined with regular physical activity, forms the foundation of effective constipation management.

The recommended daily fibre intake for adults is 25 to 30 grams. For children, a simple guide is to take the child’s age in years and add five, so a seven year old would aim for approximately 12 grams per day. Fibre is found naturally in wholegrains, cereals, fruits, and vegetables. Research has also shown that consuming two kiwifruit daily may assist with relieving constipation. For those who find it difficult to reach their fibre targets through diet alone, commercially available fibre supplements are a practical alternative. It is important to increase fluid intake alongside any increase in fibre, as fibre absorbs water and adequate hydration is necessary for it to work effectively.

Increasing dietary fibre will generally alter stool consistency. The ideal is a soft, formed stool, similar in texture to oatmeal, though firmer stools are not a concern provided they can be passed without discomfort or undue effort.

What toileting habits support bowel health?

Timing can make a meaningful difference. The bowel is most active in the morning after waking and shortly after meals, making these the most productive windows in which to attempt a bowel motion. Responding promptly to the urge to pass a motion is also important. Repeatedly suppressing this urge can contribute to the lower bowel becoming stretched and less sensitive over time.

Posture on the toilet matters more than many people realise. A position in which the knees are raised above the level of the hips, with feet flat on the floor, more closely replicates the natural squatting posture for defecation. A small footstool placed under the feet can help achieve this alignment. Reading, using a phone, or playing games while on the toilet is generally discouraged, as these activities extend toileting time and can increase straining. For children in particular, sitting for a maximum of ten minutes is advisable.

When should you see a doctor or specialist?

Laxatives can be used safely for extended periods when needed, but regular reliance on them to achieve a bowel motion is a signal that the underlying cause warrants investigation. A general practitioner can assess whether further evaluation is required and, where symptoms persist despite treatment, a referral to a specialist gastroenterologist may be recommended. Prescription therapies and more detailed assessment, including investigation of gut motility or pelvic floor function, may be considered in these circumstances.

There are also specific situations where medical attention should be sought without delay. These include a new onset of constipation without an obvious explanation, unexplained weight loss, and the presence of blood in the stool. Any meaningful change in bowel habit should always be discussed with a doctor, as further investigation may be warranted to rule out an underlying cause.

What laxative options are available?

Laxatives come in a variety of forms, including tablets, powders, syrups, fruit-based preparations, and preparations administered directly into the bowel. They fall into four main categories.

Bulking agents

Fibre based supplements work by increasing stool volume and drawing fluid into the bowel, making stools easier to pass. They are available in various forms including husks, capsules, tablets, and dissolvable powders. Starting with a small dose and gradually increasing it, while maintaining adequate fluid intake, helps minimise the side effects of bloating and wind that some people experience. Bulking agents alone may not be sufficient for moderate to severe constipation and can occasionally worsen symptoms in some patients.

Osmotic agents

These laxatives work by drawing water into the intestine to soften the stool. Several preparations in this category are also used to cleanse the bowel prior to a colonoscopy. Types include lactulose, sorbitol, magnesium-based preparations, and polyethylene glycol (macrogol) formulations, available as syrups, powders, or enemas. Potential side effects include bloating, wind, abdominal cramping, loose stools, and in young children or the elderly, a risk of dehydration.

Stool softeners and lubricants

Softening agents such as docusate work similarly to a detergent, reducing stool surface tension to make passage easier. Oil based lubricants such as liquid paraffin have also been used for this purpose, though they are not recommended immediately before sleep or for individuals who vomit regularly, due to the risk of aspiration (entering the lungs). High doses of oil-based preparations can cause leakage and underwear staining.

Bowel stimulants

Stimulant laxatives prompt the bowel wall to contract, helping move stool through the bowel. Common examples include senna, cascara, and bisacodyl, available as granules, tablets, pastes, or suppositories. Used in large quantities or over extended periods, these preparations carry a risk of low potassium levels and abdominal cramping, and should be used with appropriate caution. Substances such as liquorice, caffeine, and nicotine have mild stimulant effects on the bowel but are not considered adequate treatment for constipation.

As a general guide, it is usually recommended to begin with a bulking agent, then introduce an osmotic agent if symptoms persist, followed by the addition or substitution of a stimulant laxative if required.

Please note, this information is intended as a general educational resource for patients. It does not replace personalised advice from your treating doctor or specialist.

If you have received a referral to see one of our doctors, you can request an appointment, or contact our rooms directly on (07) 3321 1500.

This information has been sourced and adapted from education resources developed by the Gastroenterological Society of Australia (GESA).