From Ask Dr Wiki
Constipation, costiveness, or irregularity, is a condition of the digestive system where a person (or animal) experiences hard feces that are difficult to egest. It may be extremely painful, and in severe cases (fecal impaction) lead to symptoms of bowel obstruction. The term obstipation is used for severe constipation. Causes of constipation may be dietary, hormonal, anatomical, a side effect of medications (e.g. some painkillers), or an illness or disorder. Treatments consist of changes in dietary and exercise habits, the use of laxatives, and other medical interventions depending on the underlying cause.
Signs and symptoms
Constipation is one of the most common digestive complaints. It varies greatly between different people, as each person's bowel movements differ. Rate of defecation is not in itself a problem, as infrequent defecation without problems is not abnormal. Constipation is most common in children and older people, and affects women more than men. In children, constipation can lead to soiling (enuresis and encopresis). 
In common constipation, the stool is hard and difficult and painful to pass. Usually, there is an infrequent urge to void. Straining to pass stool may cause hemorrhoids and anal fissures, which are themselves painful. In later stages of constipation, the abdomen may become distended and diffusely tender and crampy, occasionally with enhanced bowel sounds.
The definition of constipation includes the following:
- infrequent bowel movements (typically 3 times or less per week)
- difficulty during defecation (straining during more than 25% of bowel movements or a subjective sensation of hard stools), or
- the sensation of incomplete bowel evacuation.
Severe cases ("fecal impaction") may feature symptoms of bowel obstruction (vomiting, very tender abdomen) and "paradoxical diarrhea", where soft stool from the small intestine bypasses the impacted matter in the colon.
The diagnosis is essentially made from the patient's description of the symptoms. Bowel movements that are difficult to pass, very firm, or made up of small rabbit-like pellets qualify as constipation, even if they occur every day. Other symptoms related to constipation can include bloating, distention, abdominal pain, or a sense of incomplete emptying.
Inquiring about dietary habits may reveal a low intake of dietary fiber or inadequate amounts of fluids. Constipation as a result of poor ambulation or immobility should be considered in the elderly. Constipation may arise as a side effect of medications (especially antidepressants and opiates).Template:Fact Rarely, other symptoms suggestive of hypothyroidism may be elicited.Template:Fact
During physical examination, scybala (manually palpable lumps of stool) may be detected on palpation of the abdomen. Rectal examination gives an impression of the anal sphincter tone and whether the lower rectum contains any feces or not; if so, then suppositories or enemas may be considered. Otherwise, oral medication may be required. Rectal examination also gives information on the consistency of the stool, presence of hemorrhoids, admixture of blood and whether any tumors or abnormalities are present.
X-rays of the abdomen, generally only performed on hospitalized patients or if bowel obstruction is suspected, may reveal impacted fecal matter in the colon, and confirm or rule out other causes of similar symptoms.
Chronic constipation (symptoms present for more than 3 months at least 3 days per month) associated with abdominal discomfort is often diagnosed as irritable bowel syndrome (IBS) when no obvious cause is found. Physicians caring for patients with chronic constipation are advised to rule out obvious causes through normal testing.
Colonic propagating pressure wave sequences (PSs) are responsible for discrete movements of content and are vital for normal defaecation. Deficiencies in PS frequency, amplitude and extent of propagation are all implicated in severe defecatory dysfunction. Mechanisms that can normalise these aberrant motor patterns may help rectify the problem. Recently the novel therapy of sacral nerve stimulation (SNS) has been utilized for the treatment of severe constipation. 
The main causes of constipation include:
- Hardening of the feces
- Paralysis or slowed transit, where peristaltic action is diminished or absent, so that feces are not moved along
- Dyschezia (usually the result of suppressing defecation)
- Constriction, where part of the intestine or rectum is narrowed or blocked, not allowing feces to pass
- Psychosomatic constipation, based on anxiety or unfamiliarity with surroundings.
- Smoking cessation (nicotine has a laxative effect)
- Abdominal surgery, other types of surgery, childbirth
In people without medical problems, the main intervention is to increase the intake of fluids (preferably water) and dietary fiber. The latter may be achieved by consuming more vegetables and fruit and whole meal bread, and by adding linseeds to one's diet. The routine non-medical use of laxatives is to be discouraged as this may result in bowel action becoming dependent upon their use. Enemas can be used to provide a form of mechanical stimulation.
In alternative and traditional medicine, colonic irrigation, enemas, exercise, diet and herbs are used to treat constipation. The mechanism of the herbal, enema, and colonic irrigation treatments often include the breakdown of impacted and hardened fecal matter.
Laxatives may be necessary in people in whom dietary intervention is not effective or is inappropriate. Most laxatives can be safely used long-term, although some are associated with cramping and bloatedness and can cause the phenomenon of melanosis coli.
Constipation that resists all the above measures requires physical intervention. Manual disimpaction (the physical removal of impacted stool) is done for those patients who have lost control of their bowels secondary to spinal injuries. Manual disimpaction is also used by physicians and nurses to relieve rectal impactions. Finally, manual disimpaction can occasionally be done under sedation or a general anesthetic—this avoids pain and loosens the anal sphincter.
Many of the products are widely available over-the-counter. Enemas and clysters are a remedy occasionally used for hospitalized patients in whom the constipation has proven to be severe, dangerous in other ways, or resistant to laxatives. Sorbitol, glycerin and arachis oil suppositories can be used. Severe cases may require phosphate solutions introduced as enemas.
Constipation is usually easier to prevent than to treat. The relief of constipation with osmotic agents, i.e. lactulose, polyethylene glycol (PEG), or magnesium salts, should immediately be followed with prevention using increased fiber (fruits, vegetables, and grains) and a nightly decreasing dose of osmotic laxative. With continuing narcotic use, for instance, nightly doses of osmotic agents can be given indefinitely (without harm) to cause a daily bowel movement.
Recent controlled studies have questioned the role of physical exercise in the prevention and management of chronic constipation, while exercise is often recommended by published materials on the subject.Template:Fact
In various conditions (such as the use of codeine or morphine), combinations of hydrating (e.g. lactulose or glycols), bulk-forming (e.g. psyllium) and stimulant agents may be necessary to prevent constipation.
Depending on the definition employed, constipation occurs in 2% of the population; it is more common in women, the elderly and children