Constipation is one of the most common health complaints, affecting up to 20% of the population. It is the reduced frequency of bowel movements requiring excessive straining at defacation in order to pass the stool.

Causes of constipation

The causes of constipation can be divided into congenital, primary, and secondary.


  • Meningocele (form of spina bifida)
  • Hirschsprung’s disease (the commonest cause of functional intestinal obstruction)


The most common cause is primary. Primary or functional constipation is ongoing symptoms for greater than six months not due to any underlying cause such as medication side effects or an underlying medical condition. In the elderly, causes include:

  • insufficient dietary fiber intake
  • inadequate fluid intake
  • decreased physical activity
  • side effects of medications
  • hypothyroidism (the thyroid gland does not produce enough thyroid hormone)
  • obstruction by colorectal cancer


  • Diet - constipation can be caused or exacerbated by a low-fiber diet, low liquid intake, or dieting.
  • Medication - many medications have constipation as a side effect (such as narcotics, diuretics, antidepressants).
  • Metabolic and muscular – problems such as hypercalcemia (an elevated calcium level in the blood), hypothyroidism (a disorder of the endocrine system), diabetes mellitus (a high blood sugar), cystic fibrosis (a genetic disorder), and celiac disease (an autoimmune disorder).
  • Structural and functional abnormalities – such as spinal cord lesions, Parkinsons (a disorder of the central nervous system), colon cancer, anal fissures, proctitis (an inflammation of the anus) and pelvic floor dysfunction.

The frequency of passing bowel motions varies greatly between individuals and as such, there is no 'normal' number of bowel movements that should be passed.

Usually it is harmless, but occasionally it may be a symptom of another disorder, including drug abuse (like heroin) or bulimia. In severe cases, it may be called obstipation, where the bowels are not moving at all.

Thyroid disorders

Thyroid disorders include hyperthyroidism (abnormally increased activity), hypothyroidism (abnormally decreased activity), and thyroid nodules, which are generally benign thyroid neoplasms, but may be thyroid cancers. All of these disorders may give rise to goiter, which is an enlarged thyroid. 

  • Hypothyroidism
Hypothyroidism is the disease state caused by insufficient production of thyroid hormones by the thyroid gland. Typical symptoms are abnormal weight gain, tiredness, baldness and cold intolerance.

Gastrointestinal motility and serum thyroid hormone levels are closely related. Hypothyroidism prominently reduces esophageal and gastric motor activity and can cause gastrointestinal dysfunction.

Anorexia Nervosa

Anorexia nervosa is an eating disorder we describe as addiction to starving. 

Constipation commonly accompanies the weight loss of anorexia nervosa. Patients may complain of bowel movements that are infrequent or small. It is helpful from the start to reassure these patients that bowel patterns in healthy patients may normally vary anywhere from two times per day to just a few times per week, and that persons with anorexia nervosa issues are expected to indeed have even fewer bowel movements. Constipation in these patients is due either to drastically reduced caloric intake, which results in reflex hypofunctioning of the colon, or to slow colonic transit.

Ovarian cancer

Ovarian cancer is a cancerous growth arising from the ovary. Symptoms are frequently very subtle early on and may include: bloating, pelvic pain, difficulty eating, and frequent urination. The symptoms are easily confused with other illnesses.

Signs and symptoms of ovarian cancer are frequently absent early on and when they exist they may be subtle. In most cases, the symptoms persist for several months before being recognized and diagnosed. Most women with ovarian cancer report one or more symptoms such as abdominal pain or discomfort, an abdominal mass, bloating, back pain, urinary urgency, constipation, tiredness and a range of other non-specific symptoms, as well as more specific symptoms such as pelvic pain, abnormal vaginal bleeding or involuntary weight loss. There can be a build-up of fluid (ascites) in the abdominal cavity.

Uterine fibroids

Uterine fibroids, also known as uterine leiomyomas or fibroids, are benign smooth muscle tumors of the uterus. Most women have no symptoms while others may have painful or heavy periods.

Complications can arise from the location of the fibroids. These complications range from intermittent bleedings to continuous bleeding over weeks, from single pain episodes to severe menorrhagia and chronic abdominal pain with intermittent spasms, from dysuria and constipation to chronic bladder and bowel spasms and even to peritonitis. Infertility may be the result of continuous metro and menorrhagia, leading to chronic infection and uterine spasms up to nonimplantation. Possible complications resulting from treatment of these disorders are haemorrhages, infection, adhesions, and secondary pain resulting from the treatment efforts.


Ovariectomy is the surgical removal of an ovary or ovaries. 

A significant proportion of women will develop new symptoms after ovariectomy, which include depression, fatigue, urinary incontinence, constipation and sexual dysfunction.

Find more about related issues


Anorexia nervosa – medical complications ―by Mehler and Brown licensed under CC BY 4.0
Constipation ―sourced from Wikipedia licensed under CC BY-SA 3.0
Oophorectomy ―sourced from Wikipedia licensed under CC BY-SA 3.0
Uterine_fibroids ―by Hic et nunc licensed under CC BY-SA 3.0
Anorexia Nervosa ―by Wilson and Wilson licensed under CC BY-SA 4.0
Constipation ―sourced from Boundless licensed under CC BY-SA 4.0
Constipation ―sourced from Queensland Government licensed under CC BY 3.0 AU
Constipation ―by Wilson and Wilson licensed under CC BY-SA 4.0
Meningocele ―sourced from Operative Neurosurgery licensed under CC BY-SA 4.0
Thyroid Gland Disorders ―sourced from Boundless licensed under CC BY-SA 4.0
Does Hypothyroidism Affect Gastrointestinal Motility? ―by Yaylali et al. licensed under CC BY 3.0
Hypothyroidism ―sourced from Boundless licensed under CC BY-SA 4.0
Ovarian Cancer ―sourced from Boundless licensed under CC BY-SA 4.0
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