What are the Causes of Constipation?

Constipation is an extremely common problem, especially in Western Countries due to intake of low fiber diet and lack of physical activity. Constipation is comparatively less common in developing and underdeveloped countries due to the consumption of a high fiber diet and regular physical activity. In developing countries also, among well-to-do persons and individuals of high class or higher middle class, constipation is a common problem, as seen in Western countries.

Constipation is a result of low (inadequate) fiber and fluid intake and increase in colonic transit time and problems in anorectal function. These are due to certain drugs, advancing age, in association with the number of systemic disorders that affect the gastrointestinal tract. Constipation can be recent onset or chronic constipation. Recent onset constipation may be due to serious organic diseases such as tumors or stricture in the gastrointestinal tract.

Causes of recent onset constipation:

1. Obstruction of colon: This may be due to tumor (malignant/benign), ischemia, and stricture or due to inflammation.

2. Spasm of anal sphincter due to painful hemorrhoids or anal fissure.

3Certain medications may also cause constipation, such as aluminum salts present in antacids.

Causes of chronic constipation:

1. IBS (irritable bowel syndrome) of constipation predominant or alternating type.

2. Certain drugs such as calcium channel blockers, antidepressants etc.

3. Hormone disturbances such as hypothyroidism, hypercalcemia, pregnancy etc.

4. Colonic pseudo-obstruction: this may result in slow colonic transit, megacolon etc.

5. Psychiatric disorders such as depression, eating disorders (anorexia nervosa), certain drugs used in psychiatric problems.

6. Neurological disorders such as Parkinsonism, multiple sclerosis, spinal cord injury etc.

7. Disorders of rectal evacuation: rectocele, rectal prolapse, pelvic floor muscle dysfunction etc.

8. Generalized muscle disorders such as systemic sclerosis.

In clinical practice physicians most commonly see idiopathic constipation and main cause being intake of inadequate fiber in diet, intake of less fluid, and inadequate physical activity.