constipation-factors, causes, symptoms, treatment


Constipation is a common term in our daily life. All of us, at some point in our life, complained about constipation. It is tough to find one who never faced constipation for once! So, in this article we will discuss detail about constipation.Lets have a look

What is constipation?

Constipation is the infrequent passage of hard stools. There is also a complaint of straining, abdominal or perianal discomfort.

So in simple terms, constipation is passing the hard stools infrequently. As the stool is hard, we need to push the stool through straining. There is a discomfort in the rectal region as the stool takes longer time to pass out of the body.

So, constipation is a common problem. It is usually a persistent, difficult, infrequent, or seemingly incomplete defecation. Thus constipation creates an uncomfortable feeling.

As our bowel habits differ from person to person, so defining constipation is difficult sometimes. As most people have at least three bowel habits per week, so when bowel movement occurs less than three bowel habits in a week, you can call it as constipation. 

Also, low stool frequency occurs in some sufferers. There is a normal frequency of defecation in many sufferers, but a problem with excessive straining, hard stools, lower abdominal fullness, or a sense of incomplete evacuation.

So it is essential to determine if it is constipation or difficulty with defecation. Because these two problems look the same, but the mode of treatment is different.

Constipation Symptoms

Symptoms of constipation are the following

  1. Passing of fewer than three stools in a week
  2. Lumpy, hard stool
  3. Have to do straining for the bowel movements
  4. Feeling of incomplete passing of stools
  5. Feeling of blockage of rectum
  6. To pass stools out of the body, one needs to use finger in the rectum, or press the abdomen with the hand.

Constipation Factors

There are several factors for constipation. These are the following

1. Stool form and consistency play an important role in constipation. Hard, pellety stools occur due to slow transit of stool through the intestine, but loose, watery stool occurs due to rapid transit of stool through the intestine. Small pellets or very large stools are more difficult to pass than normal stools, so constipation occurs.

Constipation is a perception on an individual basis. Perception of hard stool, excessive straining is a personal feeling. So if you need an enema or finger manipulation to pass the stool out from the rectum (digital disimpaction), then it is considered difficult defecation or difficulty in passing out stools.

2. Psychological factors also play a role in constipation. Some children withhold stool because they fear pain from anal irritation or maybe for gaining attention.

Many adults habitually delay or ignore the call to have a bowel movement. In many cases, this ignorance or delaying the nature’s call can cause constipation. A regular, normal bowel habit is usually not associated with constipation.

3. Chronic constipation usually occurs due to inadequate fiber or fluid intake.

4. Chronic constipation may be due to disordered colonic transit of stool or disordered anorectal function.

5. Constipation can be due to physical inactivity, physical or mental trauma.

6. Neurogastroenterologic disturbance, certain drugs, advancing age, or several diseases that affect the GI tract can cause constipation.

7. A recent appearance of constipation may be due to stricture, anorectal irritation, or a tumor. Outlet obstruction to defecation (also known as evacuation disorders) can be a cause of constipation.

8. Constipation due to any cause can become worse or may be exacerbated by hospitalization, chronic illness because these causes physical or mental trauma, inactivity, or physical immobility. So a healthy stress free lifestyle is vital to get relief from constipation.

Constipation Causes

There are wide range of causes of constipation. These are the following

Gastrointestinal causes

  1. Dietary- lack of fiber intake, lack of fluid intake
  2. Motility- Slow transit constipation, irritable bowel syndrome, chronic intestinal pseudo obstruction, Drugs
  3. Structural- Colonic carcinoma, Diverticular disease, Hirschsprung’s disease
  4. Defecation- Anorectal disease such as Crohn’s fissures, hemorrhoids, Obstructed defecation

Non-gastrointestinal causes

  1. Drugs- Opiates, Anticholinergics, Calcium antagonists, Iron supplements, Aluminium containing antacids
  2. Neurological- Multiple sclerosis, Spinal cord lesions, cerebrovascular accidents or stroke, Parkinsonism
  3. Metabolic/ Endocrine- Diabetes mellitus, Hypercalcaemia, Hypothyroidism, Pregnancy
  4. Others- Any serious illness with immobility, especially in the elderly, depression

Constipation Diagnosis

Diagnosis of constipation is based upon several consideration such as

1. The first appearance of constipation, duration and the characteristic of constipation are vital in assessing constipation and for the management. The appearance of constipation in newborns (neonatal) suggests Hirschsprung’s disease, but if there is a recent change in bowel activity in middle age, it is more likely due to a health disorder (organic disorder) such as colonic carcinoma.

2. Additionally, the presence of rectal bleeding, pain, and weight loss, excessive straining is important to note.

3. History of childhood constipation and emotional distress may indicate irritable bowel syndrome.

4. Careful examination for a general medical disorder, signs of intestinal obstruction, neurological disorders, especially spinal cord lesions, is important to determine the cause of constipation.

5. Perianal inspection and rectal examination are vital and help to find abnormalities of the pelvic floor (abnormal descent, impaired sensation), anal canal, or rectum abnormalities such as masses, fecal impaction, prolapse.

Here it is important to mention that most sufferers with constipation get relief from increased fluid intake, dietary fiber supplementation, exercise, and judicious use of laxatives.

6. Middle aged persons or elderly persons with a short history of worrying symptoms – rectal bleeding, pain, weight loss should be investigated promptly. For investigation, barium enema or colonoscopy can be done.

7. Initially, for simple constipation, digital rectal examination, proctoscopy, sigmoidoscopy (to detect anorectal disease), routine blood tests such as serum calcium and thyroid function tests, full blood count should be done. If the test reports are normal, then 1 month trial of dietary fiber and/or laxatives is justified.

8. If still symptoms of constipation persist, then colon examination by barium enema or CT colonography can be done to find out for structural disease.

Suppose no cause is detected or found, but still, the symptoms are present. In that case, referral to a specialist to investigate possible dysmotility may be needed. The problem may be due to infrequent desire to defecate (slow transit) or maybe due to neuromuscular  (nerve and muscle) incoordination and excessive straining (functional obstructive defecation).

9. Intestinal marker studies, anorectal manometry, electrophysiological studies, magnetic resonance proctography can be used to define the problem.

Constipation Evaluation

Evaluation of constipation is based upon the following

  1. A careful history of patients symptoms and confirm if the patient is actually constipated based on frequency (fewer than three bowel movements per week), consistency (lumpy/ hard), excessive straining, prolonged defecation time, need to support the perineum, digitate the Anorectum to facilitate stool evacuation.

In more than 90 percent of cases, there is no underlying cause such as depression, hypothyroidism, cancer, etc. So in the majority of cases, sufferers of constipation get relief from ample water intake, exercise, and supplementation of dietary fiber (15-25 grams per day).

2. A good diet, medication history, and looking for psychological issues are essential.

3. Physical examination, especially rectal examination, is important to rule out fecal impaction and other important diseases associated with constipation and rule out evacuation disorders such as in high anal sphincter tone, failure of perineal descent, etc.

4. For persons above 40 years old, if weight loss, rectal bleeding, or anemia with constipation present, then either flexible sigmoidoscopy plus barium enema or colonoscopy alone is required to rule out structural diseases such as stricture or cancer.

5. Measurement of serum calcium, potassium, thyroid stimulating hormone levels helps to identify persons with metabolic disorders.

People with troublesome constipation may not get relief by taking fiber alone; there is also a need for a bowel training regimen that includes taking an osmotic laxative ( such as magnesium salts, lactulose, sorbitol, polyethylene glycol) and evacuating with enema or suppository ( such as glycerin or bisacodyl) as needed.

After breakfast, a distraction free 15 to 20 minutes on the toilet without straining is encouraged. Because excessive straining may lead to the development of hemorrhoids. Suppose there is a weakness of the pelvic floor or injury to the pudendal nerve. In that case, it may result in obstructed defecation from descending perineum syndrome several years later.

People who do not get relief by simple measures or require long term treatment or fail to respond to potent laxatives need further investigation.

There are also some novel agents such as lubiprostone, chloride channel activator, linaclotide that induce secretion. These agents help to ease constipation.

Severe Constipation Investigation

Less than 5 percent of constipation sufferers have severe constipation. About 25 percent of constipation sufferers have evacuation disorder. These sufferers may need specialist (gastroenterologist) consultation.

The cause of constipation in these sufferers may be due to previously unrecognized reasons like an evacuation disorder, laxative abuse, malingering, or psychological conditions. In these sufferers, physiologic functional status of colon and pelvic floor and psychological status of sufferer determine the choice of treatment.

  1. Measurement of colonic transit- This is a radio opaque marker transit test to estimate colonic transit. It is an easy, repeatable, generally safe, inexpensive, reliable, and highly applicable test. This test is helpful for the clinical evaluation of constipation.
  2. Anorectal and pelvic floor tests- Pelvic floor dysfunction is suggested by the inability to evacuate the rectum, a feeling of persistent rectal fullness, rectal pain, the need to extract stool from the rectum digitally, application of pressure on the posterior wall of the vagina, support of the perineum during straining, and excessive straining.

A previously psychological evaluation may identify eating disorders, “control issues,” depression, or post traumatic stress disorder. Cognitive therapy or other intervention may restore the quality of life in the sufferer with chronic constipation.

Through the above mentioned test, coordination of pelvic floor muscles is tested, whether dysfunction of muscles is present or not.

A useful overall test of evacuation is the balloon expulsion test. This test can be done.

Anorectal manometry may help to find out anismus ( anal sphincter spasm). This Anorectal manometry test also helps to identify rare syndromes, such as adult Hirschsprung’s disease.

Defecography ( a dynamic barium enema including lateral views obtained during barium expulsion or a magnetic resonance defecogram) reveals changes such as anatomical defects of the rectum such as internal mucosal prolapse, enteroceles, or rectoceles.

Here it is important to note that the most common cause of outlet obstruction is the failure of the puborectalis muscle to relax. But this is not identified by barium defecography. It can be identified by magnetic resonance defecography that provides more information about the structure and function of the pelvic floor, distal colorectum, and anal sphincters.

Neurological testing (electromyography) is more helpful in evaluating sufferers with incontinence than those whose symptoms are suggestive of obstructed defecation. Suppose there is an absence of neurologic signs in the lower extremities. In that case, it suggests that any documented denervation of the puborectalis results from pelvic (e.g., obstetric) injury or from stretching of the pudendal nerve by chronic, long standing straining.

Constipation is common in sufferers of Parkinson’s disease, multiple sclerosis, and diabetic neuropathy.

Spinal evoked responses during electrical rectal stimulation or stimulation of external anal sphincter contraction by applying magnetic stimulation over the lumbosacral cord identify patients with limited sacral neuropathies with sufficient residual nerve conduction to attempt biofeedback training.

In brief, a balloon expulsion test is an important screening test for Anorectal dysfunction. 

An anatomical evaluation of the rectum or anal sphincters and an assessment of pelvic floor relaxation are the tools for evaluating patients in whom obstructed defecation is suspected and is associated with symptoms of rectal mucosal prolapse, the pressure of the posterior wall of the vagina to facilitate defecation (suggestive of anterior rectocele), or prior surgery that may be complicated by enterocele.

Constipation Relief

What treatment will be best for the sufferer depends upon the cause of constipation. After the cause of constipation is determined, treatment is given accordingly. A sufferer who develops constipation due to slow transit of stools requires aggressive medical treatment; sometimes, surgery is needed.

There are several effective constipation home remedies one can try. But those who have obstruction disorder should not try home remedies.

If the sufferer has pelvic floor dysfunction, it usually responds to biofeedback management. 60 percent of the sufferer with constipation has normal colonic transit of stool, so they are treated symptomatically.

Patients with spinal cord injury or other neurological problems require a dedicated bowel regimen including rectal stimulation, enema therapy, carefully timed laxative therapy.

Sufferers with constipation are given bulk, osmotic, prokinetic, secretory, and stimulant laxatives like fiber, psyllium, milk of magnesia, lactulose, polyethylene glycol (colonic lavage solution), lubiprostone, linaclotide, bisacodyl, prucalopride, etc.

Suppose a 3 to 6 months trial of all these medical therapies fails, in that case, when there is no obstruction in the pathway, the patient is considered for laparoscopic colectomy with ileorectostomy. But this should not be done if there is continued evidence of an evacuation disorder or generalized GI dysmotility.

The decision to resort to surgery is facilitated in the presence of megacolon and megarectum. The common complications after surgery are small bowel obstruction (11 percent) and fecal soiling, mainly at night during 1st year after surgery.

The frequency of defecation is 3-8 per day during the first year but drops to 1-3 per day from the second year after surgery.

If a sufferer with constipation has both disorders (evacuation and transit/ motility), pelvic floor retraining (biofeedback and muscle relaxation), psychological counseling, and diet modification are recommended.

Suppose symptoms are uncontrollable even after maintaining biofeedback and medical therapy, in that case, colectomy and ileorectostomy can be considered when evacuation disorder is resolved, and medical therapy fails.

In the case of a sufferer with only pelvic floor dysfunction, biofeedback training has a 70 to 80 percent success rate to relieve constipation. Regular practice of comfortable stool habits helps a lot. in fact, it is seen that a proper practice with regular timely bowel movement helps to give relief from constipation.

But it is also important to mention that when the natures call coming, one should go for the bowel movement immediately. Delaying of passing out the stool causes constipation. When you practice bowel movement on a fixed time daily, your bowel movement call comes in that fixed time after 10 to 15 days.

Attempt to manage pelvic floor dysfunction with a surgical procedure such as internal anal sphincter or puborectalis muscle division has fewer success rates. Similarly, injection with botulinum toxin also has fewer success rate and is not recommended.


  1. Harrison’s Principles of Internal Medicine 20th edition (Page 267 to Page 270)
  2. Davidson’s Principles and Practice of Medicine 23rd edition (Page 808 to Page 809)
  3. Goldman-Cecil Medicine
  4. Guyton and Hall Textbook of Medical Physiology
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