Constipation symptoms and causes


  • If you suffer from chronic constipation, it is recommended that you see your doctor.  It may indicate some underlying medical problems.
  • However, the most prevalent type of constipation is functional constipation (or chronic idiopathic constipation), which means that there are no anatomical, physiological colonic or anorectal defects. In this case, lifestyle and dietary changes may be enough to solve the constipation problem.


Constipation symptoms and causes

There are many causes of constipation. The range of constipation symptoms varies slightly, depending on the underlying cause.

This article describes the most common causes of constipation and focuses on the symptoms of the most common type, called “functional constipation”. This kind of constipation can be treated, in most cases, with natural remedies.

What is constipation?

Constipation can be broadly described as the irregularity of passing stools or the complete difficulty of emptying the bowel. It is a very common condition that affects many people of all ages and often includes otherwise healthy individuals.

In constipation, the stools may appear dry, hard and lumpy. They are often dark in color or of abnormally large or small size.

Constipation may be “casual/short-term”, when is caused, for instance, by certain foods eaten on the previous days.

It can also be “chronic”, which indicates long-term systematic causes, such as an underlying disease, frequent use of certain medications or a diet lacking in fiber.

The causes of chronic constipation can be primary and/or secondary (see below). (1, 2)

Please note, however, that normal bowel movement frequency varies between individuals. For one person, it may be normal to go to the toilet three times per day, but for another person two times per week is sufficient.

In the case of low frequency (as in the above example of twice per week), if other constipation symptoms are absent, it is generally not considered to be constipation.

However, a person having less frequent bowel movements may be considered constipated, if the frequency changed from a previous pattern.

For instance, if you usually go to the toilet once per day and suddenly your needs change to three times per week and the change is long lasting, it may indicate constipation.

Normally going to the toilet with a very low frequency, for instance once per week or even less, may also be a sign of constipation.

Constipation symptoms

The combination and the intensity of constipation symptoms may vary depending on the cause and type of constipation. They also occur in either casual or chronic constipation.

The following are the most common constipation symptoms:

  • Abdominal discomfort, cramps or pain
  • Difficulty in passing stools (straining, time taken)
  • Feeling bloated
  • Feeling of incomplete defecation
  • Feeling sick
  • Fewer than normal bowel movements (a change from frequent to infrequent)
  • Flatulence
  • Hard and lumpy stools
  • Infrequent bowel movements
  • Irregular bowel movements
  • Loss of appetite
  • Stool often dark in color

Functional constipation symptoms (chronic idiopathic constipation)

Functional constipation, also known as chronic idiopathic constipation, is the most common type of constipation.

Fortunately, it is usually resolved with some natural remedies and doesn’t require medical intervention.

Functional constipation is diagnosed if: (3, 2, 4, 5)

  1. the symptoms are present for at least three months
  2. an onset of the symptoms for at least six months
  3. loose stools are rare, except with the use of laxatives
  4. the symptoms that are specific to Irritable Bowel Syndrome are absent (such as abdominal pain or discomfort and bloating).
  5. at least two of the following symptoms occur (which happens in 25% of the cases):
    • Hard, lumpy stools
    • Straining when passing the stools
    • Sensation of incomplete excretion
    • Sensation of blockage
    • Passing stool less than three times per week
    • A need for manual manipulation to help in defecation (changing positions, manipulation with fingers, etc.)

Types and Causes of constipation

There are many types and causes of constipation which often overlap. When diagnosing constipation, doctors usually need to categorize the causes in order to establish if there is a need for further investigation and to determine the best treatment.

Therefore, constipation is divided into:

  1. Primary causes

    There are three types of primary causes: defects in the colonic function, malfunction of the defecation process and problems of the anus or rectum. These causes determine several types of constipation.

    • Normal transit constipation.

      This is also known as functional constipation (or chronic idiopathic constipation). It is related to lifestyle and diet imbalances. It is the most common type of constipation.

      “Functional”, in this context, means symptoms or problems without anatomical abnormalities. (6)

      Functional constipation is primarily characterized by two specific symptoms: hard stools and difficulty passing the stool.

      However, the actual time for the stool to move through the colon and the frequency of passing the stool is considered normal (which can be tested in a clinic).

      This type of constipation usually gets resolved with fiber supplements, higher fiber diet and/or the application of osmotic or enterokinetic laxatives.

      Please note that, if the symptoms also include bloating, discomfort or pain in the abdominal area or incomplete defecation, it may indicate Irritable Bowel Syndrome with Constipation (IBS-C). (7)

    • Slow transit constipation (STC).

      In this type of constipation, the bowel movements are not frequent and normally occur less than once per week. This condition is more common in young women and is often accompanied by bloating and discomfort in the abdominal area.

      Slow transit constipation is associated with a neuromuscular disorder of the colon. This disorder is defined by a reduced number of neurons and cells of the gut wall that are involved in the bowel movement, due to certain diseases.

      The usual treatment for this condition is laxatives. However, be aware that a high-dose usage of stimulant laxatives over the long term may slow the bowel movements.

    • Defecation (evacuation) disorders (DD).

      This type of constipation is characterized by abnormalities in the anatomy and function of the anus or rectum, resulting in constipation symptoms.

      It is associated with the difficulty in passing the stool, straining and spending a lot of time in the toilet. Hemorrhoids and fissures are common.

      This disorder is mostly behavioral related. It is associated with the avoidance of defecation due to various reasons, such as poor toilet habits or pain when defecating and can also be caused by fissures, back injuries or pregnancy related injuries. It may also be associated with eating disorders or a history of sexual or physical abuse.

  2. Secondary causes

    This can be caused by other diseases that affect the colon, anus or rectum functions, such as metabolic, neurological, systemic or psychiatric diseases. It may also be a result of mechanical obstructions (due to cancers or strictures) or by certain medications, including supplements. (8)

    • List of medications that cause constipation:
      – Anabolic steroids
      – Antacids (containing aluminum and calcium)
      – Analgesics (Non-steroidal anti-inflammatory drugs, Opioids)
      – Anticholinergics
      – Anticonvulsants
      – Antidepressants
      – Antiepileptics
      – Antihistamines
      – Antihypertensive drugs
      – Antipsychotic
      – Antispasmodic
      – Anti-Parkinsonian drugs
      – Calcium-channel blockers (to treat high BP)
      – Diuretics
      – Metal ions
      – Narcotics (used in the treatment of severe pain)
    • List of diseases that cause constipation:
      – Amyloidosis
      – Autoimmune
      – Chagas disease
      – Central nervous system lesions
      – Connective tissue disorders
      – Diabetes type 1 and 2
      – Gastrointestinal tumors or inflammation (e.g. diverticulitis IBD)
      – Hirschsprung’s disease
      – Hypoglycemia
      – Hyperglycemia
      – Hypothyroidism
      – Paraneoplastic syndromes
      – Parkinson’s disease
      – Post-viral colonoparesis
      – Pseudo-obstruction
      – Spinal or ganglion tumor
      – Spinal cord or brain injuries
      – Stroke
    • Obstruction, e.g. caused by cancer or by a narrowing part of the colon – stricture
    • Supplements, e.g. iron supplements or calcium supplements, if used in combination with another stool-binding supplements
    • Age related constipation (especially over 65 years) – deterioration of certain physiological functions and reduction in related neurons and cells
    • Other causes/risk factors that may lead to constipation
      – Dehydration
      – Sedentary lifestyle
      – Being bed-bound due to illness or accident
      – Changes in the usual diet or activities
      – Traveling
      – Pregnancy and childbirth
      – Habitual resisting bowel movements (e.g. when busy at work)

If you have been suffering from constipation for a long time, it is advisable to first see your doctor to rule out any secondary causes, which may include some serious medical conditions.

If you don’t display any signs of secondary diseases and have not been taking medications that may cause constipation, the doctors will recommend as the first step of treatment lifestyle and dietary changes that can resolve the symptoms on their own.

Some interesting facts and statistics on constipation (9)

  • About 1.5 liters of liquid passes through the colon daily from the small intestine
  • Between 200ml to 400ml of this liquid gets excreted with the stool
  • Before excreting, the stool holds the water, which can be re-absorbed back to the body, in case of dehydration
  • The longer the stool remains in the colon, the drier it becomes, making it more difficult to be excreted
  • Most studies show that the prevalence of constipation in the U.S. ranges between 12% and 19% of the population
  • In Canada, self-reported cases of constipation reach 27% of the population. (10)
  • Approximately 63 million people in North America suffer from constipation
  • 2 times more females than males suffer from constipation
  • Constipation increases with age, especially after 65 years old.


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