Constipation

Constipation means infrequent bowel movements with or without difficulty having a bowel movement. The Rome II Criteria for constipation require at least two of the following symptoms for 12 weeks or more over the period of a year:

  • Straining with more than one-fourth of defecations
  • Hard stool with more than one-fourth of defecations
  • Feeling of incomplete evacuation with more than one-fourth of defecations
  • Sensation of anorectal obstruction with more than one-fourth of defecations
  • Manual maneuvers to facilitate more than one-fourth of defecations
  • Fewer than three bowel movements per week
  • Insufficient criteria for irritable bowel syndrome
  • Straining during a bowel movement more than 25% of the time.
  • Hard stools more than 25% of the time.
  • Incomplete evacuation more than 25% of the time.
  • Two or fewer bowel movements in a week.

Causes and Risk Factors

There are numerous reasons causing constipation. Here is a list from PubMed with some modifications:

Not Enough Fiber in the Diet

Fiber—both soluble and insoluble—is the part of fruits, vegetables, and grains that the body cannot digest. Soluble fiber dissolves easily in water and takes on a soft, gel-like texture in the intestines. Insoluble fiber passes through the intestines almost unchanged. The bulk and soft texture of fiber help prevent hard, dry stools that are difficult to pass.

A low-fiber diet also plays a key role in constipation among older adults, who may lose interest in eating and choose foods that are quick to make or buy, such as fast foods, or prepared foods, both of which are usually low in fiber. Also, difficulties with chewing or swallowing may cause older people to eat soft foods that are processed and low in fiber.

Not Enough Liquids

Research shows that although increased fluid intake does not necessarily help relieve constipation, many people report some relief from their constipation if they drink fluids such as water and juice and avoid dehydration. Liquids add fluid to the colon and bulk to stools, making bowel movements softer and easier to pass. However, liquids that contain caffeine, such as coffee and cola drinks will worsen one's symptoms by causing dehydration. Alcohol is another beverage that causes dehydration. It is important to drink fluids that hydrate the body, especially when consuming caffeine containing drinks or alcoholic beverages.

Lack of Physical Activity

A lack of physical activity can lead to constipation, although doctors do not know precisely why. For example, constipation often occurs after an accident or during an illness when one must stay in bed and cannot exercise. Lack of physical activity is thought to be one of the reasons constipation is common in older people.

Medications

Some medications can cause constipation, including

  • pain medications (especially narcotics)
  • antacids that contain aluminum and calcium
  • blood pressure medications (calcium channel blockers)
  • antiparkinson drugs
  • antispasmodics
  • antidepressants
  • iron supplements
  • diuretics
  • anticonvulsants

Changes in Life or Routine

During pregnancy, women may be constipated because of hormonal changes or because the uterus compresses the intestine. Aging may also affect bowel regularity, because a slower metabolism results in less intestinal activity and muscle tone. In addition, people often become constipated when traveling, because their normal diet and daily routine are disrupted.

Abuse of Laxatives

The common belief that people must have a daily bowel movement has led to self-medicating with OTC laxative products. Although people may feel relief when they use laxatives, typically they must increase the dose over time because the body grows reliant on laxatives in order to have a bowel movement. As a result, laxatives may become habit-forming.

Ignoring the Urge to Have a Bowel Movement

People who ignore the urge to have a bowel movement may eventually stop feeling the need to have one, which can lead to constipation. Some people delay having a bowel movement because they do not want to use toilets outside the home. Others ignore the urge because of emotional stress or because they are too busy. Children may postpone having a bowel movement because of stressful toilet training or because they do not want to interrupt their play.

Specific Diseases

Conditions that can cause constipation are found below.

  • Neurological disorders
    • multiple sclerosis
    • Parkinson's disease
    • chronic idiopathic intestinal pseudo-obstruction
    • stroke
    • spinal cord injuries
  • Metabolic and endocrine conditions
    • diabetes
    • uremia
    • hypercalcemia
    • poor glycemic control
    • hypothyroidism
  • Systemic disorders
    • amyloidosis
    • lupus
    • scleroderma

Problems with the Colon and Rectum

Intestinal obstruction, scar tissue—also called adhesions—diverticulosis, tumors, colorectal stricture, Hirschsprung disease, or cancer can compress, squeeze, or narrow the intestine and rectum and cause constipation.

Problems with Intestinal Function

Idiopathic—of unknown origin—constipation does not respond to standard treatment.

Functional constipation means that the bowel is healthy but not working properly. Functional constipation is often the result of poor dietary habits and lifestyle. It occurs in both children and adults and is most common in women. Colonic inertia, delayed transit, and pelvic floor dysfunction are three types of functional constipation. Colonic inertia and delayed transit are caused by a decrease in muscle activity in the colon. These syndromes may affect the entire colon or may be confined to the lower, or sigmoid, colon.

Pelvic floor dysfunction is caused by a weakness of the muscles in the pelvis surrounding the anus and rectum. However, because this group of muscles is voluntarily controlled to some extent, biofeedback training is somewhat successful in retraining the muscles to function normally and improving the ability to have a bowel movement.

People with IBS having predominantly constipation also have pain and bloating as part of their symptoms.

Signs and Symptoms

Signs and symptoms associated with diarrhea may include:

  • Infrequent bowel movements
  • Painful bowel movements
  • Difficulty moving bowel
  • Abdominal pain
  • Bloating
  • Nausea
  • Vomiting
  • Blood in the stool

Diagnosis and Treatment

Diagnosis is based on a history and physical examination, with one or more of the following tests:

  • Blood works
  • Stool studies
  • X-ray
  • CT scan
  • Endoscopy
  • Colonoscopy
  • EUS
  • MRI

Treatment is based on the cause, and focused on getting rid of the causative factor, relief of symptoms, etc.

References:

  1. PubMed.
  2. Wikipedia.
  3. Mayo clinic online health information.
  4. Sleisenger and Fordtran's Gastrointestinal and Liver Disease- by Mark Feldman MD, et al.
  5. The Little Black Book of Gastroenterology-by David W. Hay.
  6. Principles of Clinical Gastroenterology by Tadataka Yamada, et al.


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