Seek emergency medical care if severe abdominal pain, marked swelling, vomiting, fever, or inability to pass gas occurs. Do not wait for constipation to last a particular number of days before seeking help.
Medical Conditions That Can Cause Chronic Constipation
Constipation is a symptom rather than a disease in itself. Identifying the underlying cause is essential for choosing the right treatment.
1. Slow-Transit Constipation
In some people, the colon moves stool unusually slowly.
This condition is known as slow-transit constipation. The muscles and nerves responsible for moving intestinal contents may not function efficiently.
Because stool remains in the colon longer, more water is absorbed, making it harder and drier.
People with slow-transit constipation may experience:
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Very infrequent bowel movements.
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Little or no urge to defecate.
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Significant bloating.
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Hard stools.
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A poor response to ordinary dietary changes.
Some patients require specialized testing to measure how quickly material moves through the colon.
2. Pelvic Floor Dysfunction
The pelvic floor is a group of muscles that supports the pelvic organs and helps control bowel movements.
During defecation, these muscles must relax in a coordinated way.
In people with pelvic floor dyssynergia, the muscles may contract instead of relaxing, making it difficult to pass stool.
Common symptoms include excessive straining, prolonged time on the toilet, a sensation of blockage, and incomplete evacuation.
Treatment may include pelvic floor physical therapy and biofeedback training.
3. Irritable Bowel Syndrome With Constipation
Irritable bowel syndrome, or IBS, is a disorder of gut-brain interaction.
People with IBS may experience abdominal pain associated with changes in bowel habits. Some have constipation as their predominant symptom, while others experience diarrhea or alternating patterns.
IBS with constipation is different from simple slow bowel movements because abdominal pain is a defining feature of the condition.
Dietary adjustments, stress management, medications, and other individualized treatments may help control symptoms.
4. Neurological Disorders
The nervous system plays an important role in regulating intestinal movement.
Conditions that affect the brain, spinal cord, or peripheral nerves can interfere with normal bowel function.
Examples include:
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Parkinson's disease.
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Multiple sclerosis.
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Spinal cord injuries.
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Stroke.
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Diabetic autonomic neuropathy.
In some patients, constipation develops gradually as the neurological condition progresses.
A treatment plan may need to address both bowel function and the underlying neurological disorder.
5. Endocrine and Metabolic Conditions
Hormonal and metabolic changes can also affect intestinal movement.
Hypothyroidism, in which the thyroid gland produces insufficient hormones, may slow many body processes, including digestion.
High blood calcium levels can contribute to constipation. Diabetes may also affect intestinal nerves in some individuals.
When constipation develops without an obvious explanation, clinicians may consider blood tests based on the patient's symptoms and medical history.
Medications That May Make Constipation Worse
Medication-related constipation is common and sometimes overlooked.
Several groups of medicines can slow bowel movement or make stool harder.
Examples include:
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Opioid pain medications.
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Certain antidepressants.
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Some antihistamines.
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Anticholinergic medicines.
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Iron supplements.
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Calcium supplements.
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Certain blood pressure medicines, including some calcium channel blockers.
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Some antacids containing aluminum or calcium.
Opioids deserve particular attention because they act on receptors in the digestive tract and reduce intestinal movement.
People who need long-term opioid treatment may require a preventive bowel regimen prescribed by their healthcare professional.
If constipation begins after starting a medication, discuss it with a doctor or pharmacist. Do not stop a prescribed medicine without professional guidance.
How Doctors Diagnose the Cause of Constipation
There is no single test that identifies every cause of constipation.
Doctors usually begin by reviewing the patient's medical history and asking detailed questions about bowel habits.
They may ask:
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How often do bowel movements occur?
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Are stools hard, dry, or difficult to pass?
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Is there excessive straining?
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Does the patient feel that the bowel has not emptied completely?
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Is there abdominal pain or bloating?
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When did the symptoms begin?
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Have there been changes in weight or appetite?
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What medications and supplements are being used?
A physical examination may include an abdominal examination and, when appropriate, a digital rectal examination.
Additional investigations depend on the suspected cause.
Blood Tests
Blood tests may help identify conditions such as hypothyroidism, anemia, electrolyte abnormalities, or metabolic disorders.
Not every person with uncomplicated constipation needs extensive blood testing.
Colonoscopy
A colonoscopy allows a doctor to examine the inside of the colon using a flexible camera.
It may be recommended when there are warning signs such as unexplained rectal bleeding, anemia, unexplained weight loss, or a significant change in bowel habits.
It is also used for colorectal cancer screening according to age and individual risk.
Colonoscopy is not routinely necessary for every person with constipation.
Abdominal Imaging
An abdominal X-ray or CT scan may be used when obstruction, severe fecal loading, bowel dilation, or another abdominal complication is suspected.
Imaging can be especially important when symptoms suggest toxic megacolon or bowel perforation.
Specialized Bowel Function Tests
For people with persistent constipation that does not improve with standard treatment, doctors may recommend tests such as:
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Colonic transit studies.
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Anorectal manometry.
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Balloon expulsion testing.
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Defecography.