Constipation

Constipation describes infrequent bowel movement, often with hard, dry stool that is difficult to pass. It may be associated with bloating, straining and pain. It is caused by inadequate muscle contraction of muscles or over absorption of water.
Though the is huge variance in frequency of bowel movement between individuals; less than three per week comes within the definition of constipation.

Causes
• Diet low in fibre
• Medications such as painkillers of the opioid type, antacids of aluminium and calcium, anti-depressants, anti-convulsants, iron supplements, diuretics, laxatives (long term use can result in secondary constipation)
• Irritable bowel syndrome
• Lifestyle: many individual factors may cause constipation. Lack of exercise and constipation is associated with constipation. Ignoring the urge to pass stool over a long period may result in chronic constipation. A sudden change in schedule may result in constipation as may happen when travelling.
• Dehydration
• Electrolyte abnormalities such as high levels of calcium in the blood or low levels of potassium
• Slow transit constipation is a condition in which the passage of faecal/faeculent matter through the colon is impaired or delayed. The causes is unknown but is believed to be caused by myopathy (disorder of muscle) or neuropathy (neurological disorder)
• Pregnancy
• Neurological disorders such as Parkinson's disease, multiple sclerosis, spinal cord injuries and Hirschsprung's disease, in which absent nerves impair colonic function
• Diabetes
• Uraemia
• Hypothyroidism, malfunction of the thyroid gland
• Amyloidosis
• Diagnosis

The physician will take a medical history, asking questions regarding diet, the timing and nature of symptoms, the person’s age, associated features such as mucus or blood in the stools and weight loss.
The physician may also perform a digital rectal examination. For this examination the patient lies on his or her side so that the anus is accessible. The physician inserts a finger into the anus and assess the muscle tone of the sphincter. Then the physician advances his or her finger and palpates the inside of the rectum. The physician then withdraws the finger and checks the glove for blood and mucous.

Blood tests may be performed to check the electrolyte levels, glucose levels and thyoid function.
Specific investigations called transit studies may be necessary to diagnose slow transit constipation. This assesses the movement of food through the colon. The patient swallows capsules containing small markers that are visible on an x ray. The movement of the markers through the colon is monitored by abdominal x rays taken several times 3 to 7 days after the capsule is swallowed. The patient eats a high-fiber diet during the course of this test.
X-rays with barium contrast (see barium enema) may be performed. This is simply an x-ray in which the rectum and colon are filled with a substance called barium. This allows the lining of the colon to be directly visualised, facilitating diagnosis.
Colonoscopy or sigmoidoscopy may be performed in order to visualise the lining of the colon and rectum. This involves advancing a lighted instrument (sigmoidoscope or colonoscope) into the colon. In the case of the colonoscope, an image is transmitted onto a screen, allowing abnormalities to be detected.
Anorectal manometry evaluates anal sphincter muscle function. For this test, an air-filled balloon is inserted into the anus and then retracted to measure tone of the sphincter muscle.


Treatment
Treatment for constipation depends on identification and correction of the underlying cause. This may involve:
Increasing the amount of fibre in your diet by taking supplements or eating wholegrain bread and cereal, vegetables and fruit.
Changing your existing medication.
Cha nges in lifestyle such as getting more exercise and passing stool on urge sensation.
Increasing fluid intake
Conrol of diabetes
Correction of electrolyte abnormalities
Thyroid hormone replacement
Surgery may be required in certain cases, such as slow transit constipation or Hirschsprung's disease.
If the above changes have had no effect, the physician may decide to prescribe laxatives. There are many types of laxatives and the physician will decide the most suitable type for you.

Complications
Complications may include haemarrhoids, anal fissures (tears of anal skin which may lead to bleeding) and rectal prolapse (protrusion of the rectum through the anus).
These conditions may require surgery. Another complication, called faecal impaction, may occur when the rectum and bowel become so packed with faeces that they cannot eliminate it. This requires treatment with an agent that softens the impacted faeces, allowing their manual removal. This may be taken orally or by enema.