Which medical conditions are associated with constipation?
Constipation is not always due to diet or lifestyle. Sometimes, ongoing trouble passing stools is a sign of another health condition.1 These can include conditions affecting the nerves, the hormones, the immune system, or the structure of the bowel itself.2 When another condition is the cause, treating that condition is usually an important part of managing the constipation.3 Constipation is common, affecting around 16% of adults worldwide, and it becomes more common with age — partly due to age-related changes in the nerves and muscles of the bowel.2,3
Is constipation a comorbidity?
A comorbidity is a health condition that occurs alongside another one. Yes. Constipation often occurs alongside other health conditions. In a large community study, people with long-term constipation were more likely than others to also have Parkinson’s disease or multiple sclerosis.4 It is also linked to anxiety and depression.2
What conditions are associated with constipation?
Constipation is usually grouped into two types. In “primary” constipation, no underlying illness is found behind it — this is the everyday kind, and it includes constipation that is part of irritable bowel syndrome (IBS) and problems with the muscles used to pass a stool.1 In “secondary” constipation, another health problem or a medicine is the cause.1 This article focuses mainly on those secondary causes, which fall into a few groups.
Nerve conditions. The nerves help control how the bowel moves, so conditions that affect them may lead to constipation.3 Parkinson’s disease is one example, where constipation is common and can appear early.5 Multiple sclerosis, stroke and spinal cord injury are other examples.2
Hormone and metabolism conditions. An underactive thyroid, diabetes, an overactive thyroid, high calcium and pregnancy can all play a part.2 Low potassium may too.3
Medicines. Many everyday medicines may cause constipation, including strong painkillers (opioids), some antidepressants, iron tablets and certain blood pressure medicines.2
Autoimmune conditions. Systemic sclerosis (also called scleroderma) is one example. It affects the gut in most people who have it, and can affect the bowel too.6 When it affects the large bowel, constipation can happen because the bowel muscle wastes away and its nerves are damaged, so the bowel cannot move stool along properly.6
Structural bowel conditions. Some problems change or block the shape of the bowel and may cause constipation. These include bowel cancer, a narrowing of the bowel, diverticular disease, and a bulging or slipping of the back passage (rectocele and rectal prolapse).2
Mental health conditions. Depression, anxiety and eating disorders are each linked to constipation.2
Can constipation cause other health problems?
Yes. Constipation may be uncomfortable but is not usually serious.2,4,7 However, if it is severe or carries on for a long time, it can sometimes lead to other health problems which it is worth knowing about.
Stuck stool (faecal impaction). Hard stool can build up and become difficult to pass. This can cause stool to leak around the blockage, sores in the bowel lining, and bleeding.3 In severe cases, constipation can block the bowel and may need surgery.2
Tummy and digestion symptoms. Some people whose constipation comes with pain may also notice upper-gut symptoms such as heartburn or indigestion.1
Everyday life. Constipation can lower quality of life. In a large community study, people with more severe constipation had lower quality of life across every area measured.7 General health, mental wellbeing and social life can all be affected.2
Warning signs. Constipation that is new or getting worse for no clear reason could be a sign of another health problem — even though the constipation itself is not the cause. Some things are worth getting checked. These include a change in your usual bowel habits after the age of 50, or constipation that starts suddenly later in life. They also include blood in your stools, losing weight without trying, or feeling very tired (which can be a sign of low iron, called anaemia). A strong family history of bowel cancer matters too. If you have any of these, or you are worried, see your doctor.2
What you can do
If another condition is causing your constipation, the first step is usually to treat that condition.2
Healthy habits still help too: getting enough fibre and staying active are a sensible starting point.8
Drinking enough fluid matters as well, although drinking extra beyond what your body needs has not been shown to relieve constipation on its own.8
If you think a medicine might be part of the problem, talk to your doctor before you stop or change it — they can look at whether any of your medicines could be adding to it.2,8
If lifestyle measures are not enough, a laxative may be an alternative option. A pharmacist or doctor can advise whether a laxative is right for you 1
See a doctor if you have new constipation with no clear cause, or if your usual bowel pattern suddenly changes — especially alongside bleeding or weight loss you cannot explain.2
Conclusion
Constipation is not always down to diet or lifestyle. It can be caused by another health condition — including conditions that affect the nerves or hormones, autoimmune conditions, structural problems of the bowel, and some mental health conditions — or by certain medicines.2,6 Long-term constipation can also bring problems of its own, such as a lower quality of life.7 Where another condition is the cause, an important step is to find and treat it, alongside healthy habits such as getting enough fibre and staying active.2,8 Constipation that lasts, is severe, or changes — especially alongside warning signs such as bleeding or unexplained weight loss — should be checked by a doctor.2
This article provides general health information only and is not a substitute for personalised medical advice. The availability and approved indications of medicines may vary by country. Always consult a qualified healthcare professional before starting any new treatment.
FAQ
Constipation can be caused by a number of other health conditions. These include conditions that affect the nerves (such as Parkinson’s disease, multiple sclerosis, stroke and spinal cord injury) and conditions that affect hormones and metabolism (such as an underactive thyroid, diabetes and high calcium levels).2 Autoimmune conditions such as systemic sclerosis (scleroderma), structural problems of the bowel (such as bowel cancer and diverticular disease), and mental health conditions (such as depression and anxiety) are also linked.2,6 Certain medicines can cause constipation too.2
Many common medicines can cause or worsen constipation. These include strong painkillers (opioids such as morphine and codeine), some antidepressants, iron and calcium supplements, certain blood pressure medicines, antacids containing aluminium or calcium, and some medicines for Parkinson’s disease, seizures or mental health conditions.2 Opioids in particular can cause constipation because they slow down how the gut moves.2 If you think a medicine might be causing constipation, talk to your doctor before stopping or changing it.2
Constipation is often linked with psychological factors, including anxiety, depression, stressful life events and eating disorders.2 The relationship is complex, and it is not always clear whether one leads to the other.2 One study even found no clear link between psychological distress and how often people opened their bowels in one type of constipation (where the bowel empties slowly).2 If constipation is affecting your wellbeing, it is worth speaking to a doctor.
Yes. Problems with the pelvic floor — the muscles that help control bowel movements — are one of the main recognised causes of long-term constipation.1 Passing a stool relies on these muscles and the muscles around the back passage working together, and when they do not relax or coordinate properly, stool can be hard to pass.1,3 This is sometimes called a defecatory disorder, and it can often be helped with a treatment called biofeedback, which helps retrain the muscles.1,2
In some cases, new or changing constipation can be a warning sign that should be checked. Constipation that is new or getting worse for no clear reason — especially after the age of 50, or alongside blood in your stools or unexplained weight loss — is the kind of warning sign that prompts doctors to look for an underlying cause such as bowel cancer.2 Constipation is usually not a serious problem, but these particular symptoms should always be checked by a doctor.2
This article was written with the assistance of generative AI technology and reviewed for accuracy.
