Constipation: Causes, Clinical Features, Prevention & Treatment


Constipation refers to an abnormal or irregular bowel movement or irregularity in defecation with abnormal hardenings of stools which makes it difficult to pass the stool and sometimes can be painful. A decrease in stool volume, or retention of stool in the rectum for a longer period often with a feeling of incomplete evacuation after defecation. A bowel movement less than 3-4 times per week is considered as constipation. Simply, constipation is difficulty in passing the stool which is hard and painful.

The pathophysiology of constipation is poorly understood,  however it is thought to involve interruption with one of three major functions of the colon:

  • mucosal transport  which is mucosal secretions facilitate the movement of colon contents
  • myoelectric activity is the Mixing of the rectal mass and propulsive actions
  • The process of defecation  (e.g. pelvic floor dysfunction)

Any of the causative factors previously identified can interfere with any of these three processes.


  • It  can be caused by certain medications such as tranquillizers, anticholinergic, antidepressants, antihypertensive, bile acid sequestrants, diuretics, opioids, aluminium based antacids, iron preparation, selected antibiotics and muscle relaxants.
  • Rectal or anal disorders, obstruction, metabolic, neurologic and neuromuscular conditions; endocrine disorders; lead poisoning; connective tissue disorders and variety of disease also cause constipation.
  • Other causes may include weakness, immobility, debility fatigue and inability to increase intra-abdominal pressure to pass stool.
  • Diseases of colon commonly associated with constipation include irritable bowel syndrome and diverticular disease.
  • It can also occur with an acute process in the abdomen  likewise appendicitis.
  • It is also a result of dietary habits  (i.e. low consumption of fiber and inadequate fluid intake).
  • Lack of regular exercise or a sedentary lifestyle and a stress-filled life.
  • Chronic use of laxative may also contribute to this problem.

Clinical features

  • Less than three bowel movement per week
  • Abdominal distension
  • Pain and pressure
  • Decreased appetite
  • Headache
  • Fatigue
  • Indigestion
  • A sensation of incomplete evacuation
  • Straining at stool
  • Elimination of small volume, lumpy, hard, dry and bloody stool.

Complications such as haemorrhoids, anal fissures, faecal impaction and mega colon.  


Haemorrhoids and anal fissures can develop as a result of constipation. Haemorrhoids develop as a result of perianal vascular congestion caused by Straining. Anal fissures may result from the passage of the hard stool through anus, tearing the lining of the anal canal.

Faecal impaction occurs when an accumulated mass of dry faeces cannot be expelled. The mass may be palpable on digital examination, may produce pressure on the colonic mucosa that results in ulcer formation, and frequently causes seepage of liquid stools.

Megacolon is a dilated and atonic colon caused by faecal mass that obstructs the passage of colon contents. Symptoms include constipation, liquid faecal continence and abdominal distension. Megacolon can lead to perforation of the bowel.

Diagnostic tests

  • The diagnosis of constipation is based on the one’s medical history, physical examination.
  • Sigmoidoscopy
  • Stool test for occult blood
  • Anorectal manometry (pressure studies  such as a balloon expulsion test) may be performed to assess malfunction of the sphincter.
  • Defecography and colonic transit studies can also assist in the diagnosis because they permit assessment of active Anorectal function.
  • Newer tests such as pelvic floor magnetic resonance imaging  (MRI) may identify occult pelvic floor defects (Ginsberg, et al., 2007)


It is  somehow possible to prevent constipation however it cannot always be prevented

  • Have a healthy bowel habits ( maintain a daily need to go for elimination )
  • Emphasise on responding to the urge to defecate.
  • Intake fibre containing  foods such as green vegetables, fruits (selectively some fruits can cause constipation too), whole grain foods, cereal and oats. Have a small but frequent servings in a day
  • Intake plenty of water or any kind of fluids
  • Try to minimize the consumption of caffeine and tea
  • Avoid smoking cigarettes ( some cannot pass stool until they smoke early morning which eventually becomes a habit)
  • Regular exercise or even a walk is helpful enough to facilitate bowel movements
  • Avoid overuse of laxatives without concerning a doctor because they can weaken colonic function.
  • Elderly consideration as elder people are more prone to constipation.
  • The normal position  (semisquatting) can maximise the use of abdominal muscles and force of gravity.


Treatment targets the underlying cause of constipation and aims to prevent reoccurrence.

  • It includes bowel habit training, increased fiber and fluid intake, judicious use of laxatives.
  • Management may also include discontinuing laxative abuse.
  • Routine exercise to strengthen abdominal muscles is encouraged.
  • Daily dietary intake of  25 to 30 g/day of fiber (soluble and bulk forming) is recommended especially for the elderly patients.
  • If laxative use is necessary, one of the following may be prescribed : bulk forming agents, saline and osmotic agents, lubricants, stimulants or faecal softeners
  • Enemas and rectal suppositories are generally not recommended for treating constipation they should be prescribed only for the treatment of fecal impaction.
  • Treatment for impaction removal can be embarrassing and painful as it usually requires digital dislodgement with enema administration.
  • Specific medications may be prescribed to enhance colonic transit by increasing propulsive motor activity
  • These medications may include cholinergic agents, cholinesterase inhibitors or prokinetic agents. They should only be used for the patients with unremitting constipation.


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