Constipation in the Elderly: Causes, Risk Factors, Complications, and Treatment Options

Constipation is a common health concern in older adults, affecting between a quarter and nearly a third of people aged over 65 worldwide. ¹ It is not always part of ageing, but it is closely linked to many of the changes that come with getting older. Understanding why it happens, what can make it worse, and what can be done about it can help older people and their carers feel better informed and less isolated in dealing with this often-overlooked condition.

What Are the Risk Factors for Constipation in Older Adults?

Constipation in later life rarely has a single cause. In many older adults, it results from several overlapping factors that accumulate with age. ¹ Recognising these factors is the first step toward managing them.

Physiological changes with ageing. As the body ages, bowel function changes. Colonic transit time becomes longer, the urge to defecate may become less reliable.¹ These internal changes alone can slow the passage of stool through the gut, even in the absence of other contributing factors.

Reduced physical activity. Movement stimulates the bowel. Many older adults become less physically active due to mobility limitations, pain, fatigue, or illness. A sedentary lifestyle is a risk factor for constipation.^1,2

Inadequate fluid and fibre intake. Low dietary fibre intake has been identified as a risk factor for constipation in some, but not other studies.² Adequate fluid intake is important for normal bowel function. For those taking lactulose (Duphalac), drinking 1.5–2 litres of fluid a day is recommended by the manufacturer.³

Multiple medications (polypharmacy). Older adults are more likely to take several medications simultaneously, many of which can slow bowel motility. Opioid pain medicines, anticholinergic drugs (used for bladder problems, depression, or allergies), calcium channel blockers (for heart disease), iron supplements, and certain antacids are all known contributors to drug-related constipation.^1,2

Chronic health conditions. Conditions such as Parkinson’s disease, diabetes mellitus, hypothyroidism, depression, and cognitive impairment are associated with constipation. These conditions may affect bowel function directly, or indirectly through reduced physical activity, neuropathies, or the effects of medications used to treat them.² Depression has also been identified as a risk factor for constipation, highlighting the important connection between emotional wellbeing and bowel health.²

Institutional care. Constipation is considerably more common in older adults living in nursing homes or hospital settings than in those living independently in the community.² The reasons for this are multiple and not fully explained by medication effects alone,² and laxative use among nursing home residents is reported to be as high as 50%.¹

Once the causes are understood, it becomes clear why constipation often goes unaddressed in older people who may feel embarrassed to mention it or assume it is simply part of growing old. It is not, and it can be helped.

Which Factors Can Increase an Older Person’s Risk of Constipation?

Several factors are particularly important because they tend to occur together in older adults, compounding the risk of constipation.^1,2 Polypharmacy is considered an important cause of constipation in older adults. Older adults often have multiple comorbidities and take multiple medications, which should be taken into account when considering a new treatment.¹ Reduced physical activity, lower dietary fibre intake, and the presence of multiple chronic conditions all interact to make constipation harder to prevent and treat in this age group.^1,2

Constipation in older adults affects women disproportionately, with elderly women experiencing severe constipation at rates two to three times those seen in elderly men.¹ Older adults living in nursing homes or institutional care settings are also at significantly higher risk than those living independently in the community, a difference that is not fully explained by medication effects alone.²

It is worth remembering that constipation in older adults is often distressing beyond the physical discomfort. Many people feel frustrated, embarrassed, or anxious about it, and this emotional burden can itself exacerbate gut-brain responses that slow motility. Acknowledging this dimension — rather than treating it purely as a plumbing problem — leads to kinder and more effective care.

What Is Faecal Impaction in the Elderly?

Faecal impaction is a serious complication of untreated or poorly managed constipation, and it is far more common in older adults than is often appreciated. It occurs when hardened stool accumulates in the rectum or colon and cannot be passed through normal peristaltic effort.⁴ It is estimated that half of institutionalised elderly people experience faecal impaction over the course of a year.⁴

Faecal impaction is associated with significant morbidity and can be fatal if its complications are not recognised.⁴ It can also present in misleading ways — rather than obvious constipation, older people with faecal impaction may develop what appears to be diarrhoea or anal incontinence, a consequence of increased colonic secretion combined with the reduced sphincter tone commonly seen in older adults.⁴ If left untreated, faecal impaction can cause serious complications including colonic ulceration and bowel perforation, which can be fatal.⁴

The main risk groups for faecal impaction are older adults, people with underlying neuropsychiatric conditions, and those who are hospitalised or in institutional care. ⁴

Because faecal impaction tends to recur, prevention should be considered, and may include laxatives along with adequate fibre and water intake.⁴

What Options Are Available for Treating Constipation in Elderly People?

Treatment in older adults generally starts with lifestyle and dietary measures, then progresses to medication when these are insufficient.¹ The goal is soft, regular stools achieved with the least possible disruption to comfort.

Lifestyle measures — increased fluid intake, more dietary fibre, and gentle physical activity where possible — are recommended as the first steps in managing constipation in older adults, though many will be unable to achieve adequate relief through these measures alone.¹

Establishing a regular toileting routine after meals may also be helpful, taking advantage of the body’s natural gastrocolic response — particularly for those who retain sufficient mobility and routine to make this practical.

Bulk-forming laxatives, such as psyllium and bran, work by adding fibre to the stool and helping it hold water, which makes it softer and easier to pass. Most guidelines suggest fibre as a primary option for older adults with constipation. However, some older people find bulk laxatives difficult to swallow, and in this situation a syrup-type osmotic laxative may be recommended instead.¹

Osmotic laxatives have been shown to be effective in elderly patients with constipation. In placebo-controlled trials, lactulose, lactitol, and polyethylene glycol (PEG) all significantly increased defecation frequency, improved stool consistency, and reduced the need for additional laxatives. Most guidelines position osmotic laxatives as second-line treatment after fibre because they are effective, generally well-tolerated, and inexpensive. ¹

Stimulant laxatives, such as senna and bisacodyl, work by encouraging the bowel to move. Stimulant laxatives are generally recommended for short-term use — within a few months — because longer-term use may lead to loss of water and salts, fatty stools, or other complications. Most guidelines recommend trying them when bulk laxatives (fibre) or osmotic laxatives have not provided enough relief. ¹

Stool softeners are another option, although they have been less well studied in older adults than other types of laxative. The available evidence suggests they can help improve overall symptoms, though their effect on how often you go to the toilet is less clear-cut. Different preparations of stool softener seem to work in slightly different ways.¹

Newer prescription medications are also available. These work in different ways from traditional laxatives and some have been shown to be effective in older adults.¹

Is Lactulose suitable for Elderly People?

Lactulose is generally considered suitable for use in elderly people and has been studied specifically in this group, including in nursing home residents.¹ Lactulose is an osmotic laxative that is used to treat constipation by regulating the physiological rhythm of the colon.³ Because lactulose is poorly absorbed by the small intestine, it stays in the gut and does its work locally — an important advantage in older adults who may already be taking several medications.³

In the colon, lactulose is broken down by colonic bacteria into organic acids that lower pH, draw water into the colon, soften stool, and stimulate peristalsis.³ In a double-blind, placebo-controlled study, lactulose syrup was significantly more effective than placebo in achieving treatment success in constipated patients, with response rates of 86% versus 60% respectively.⁶ In two clinical trials, lactulose helped people go to the toilet more often than placebo, and also reduced how much they needed to rely on other laxatives. ¹

Gas is a common side effect, which typically settles within the first few days of treatment.³ Abdominal discomfort may also occur.³ Higher or prolonged doses may cause diarrhoea or affect the body’s mineral balance — so it is important not to exceed the recommended dose.³ Lactulose is contraindicated in people with galactosaemia or gastrointestinal obstruction.³ Dose should always be guided by a healthcare professional.

What You Can Do

If you are an older adult experiencing constipation, or caring for someone who is, a few steps can make a real difference. First, do not accept constipation as inevitable — it is treatable. Speak openly with a pharmacist or doctor about symptoms, any medications that may be contributing, and what relief options are appropriate.

In daily life, aim to: drink adequate fluids throughout the day (approximately 1.5 to 2 litres); include fibre-containing foods such as vegetables, fruits, and whole grains where possible; stay as physically active as comfort and health allow; and try to establish a regular toileting routine after meals. If lifestyle changes alone are not enough, ask a healthcare professional about appropriate medications to treat constipation.

Carers and healthcare workers may find it helpful to keep bowel health in mind for older adults in their care, particularly those with neuropsychiatric conditions, reduced mobility, or who are taking opioid medicines, as these individuals may be at greater risk of faecal impaction.

Conclusion

Constipation in older adults is common, often overlooked, and rarely has a single cause. It develops from a combination of physical changes with age, lifestyle factors, medications, and underlying health conditions — and when left unaddressed, it can progress to serious complications including faecal impaction. With the right combination of lifestyle support, early recognition, and appropriate laxative therapy where needed, many older adults can achieve meaningful relief. A healthcare professional can help identify a suitable approach for the individual.

FAQ

This article was written with the assistance of generative AI technology and reviewed for accuracy.