Constipation: Treatment

Treatment of any identified cause should be attempted before medications are considered. Unfortunately, most constipation treatments are not well-supported by clinical trials.

For idiopathic constipation, the most effective treatment is to stepwise increase fiber intake and fluids, consume foods that reduce transit time (see Nutritional Considerations), and take advantage of the body's normal rhythms of colonic motility, which occur after meals, especially in the morning.

Biofeedback and behavioral changes may be helpful in outlet dysfunction, especially in children.

Severe constipation may require a multidimensional approach that includes manual disimpaction.

Drug Therapy

Many of the following drugs can be used in children, but doses must be adjusted accordingly. Many of these remedies are available in oral form and as rectal suppositories and enemas.

Simple therapies, such as those mentioned above, supplemental corn syrup and fruit juices with sorbitol (for infants already eating solid foods), should be tried first. Enemas and stimulant laxatives should not be used in infants.

Laxatives are not generally recommended, because they prevent the bowel from recovering normal function and often need to be continued. Although they are generally well-tolerated, laxatives may cause abdominal distention, nausea, anorexia, cramps, gas, and (rarely) malabsorption or dangerous electrolyte imbalances, which may worsen with continual use. Laxative abuse is common and often hidden. Clinicians should try to wean patients from laxatives for these reasons.

Bulk-forming agents (eg, oral fiber supplements such as psyllium, methylcellulose, and polycarbophil) hold water in the intestinal contents, making them easier to pass.

Emollients, such as docusate and mineral oil, soften stools, but are not very effective.

Hyperosmolar agents, which cannot be absorbed, produce diarrhea through an osmotic fluid shift. These include:

• Magnesium salts are effective for rapid emptying and intended for one-time use. Hypermagnesemia can occur with frequent use.
• Lactulose works more slowly than salts, and may be used for long-term treatment when diet therapy is not possible or ineffective. It may cause gas.
• Sorbitol is less expensive than lactulose and functions similarly.
• Glycerin is available as a suppository.
• Polyethylene glycol (MiraLax) formulations have varying electrolyte compositions. Although still relatively expensive, they may produce less gas than sorbitol and lactulose.

Stimulants or contact irritants increase peristalsis. They include senna, bisacodyl, and castor oil. These agents are not for chronic use, as they may cause electrolyte abnormalities.

Additional Treatments for Adult Patients

Drugs that act as prokinetics may be helpful (an exception is metoclopramide, which has not been shown to be helpful for severe constipation). Effective agents include:

• Misoprostol⁵ and colchicine.⁶
• Tegaserod, a serotonin agonist (5-HT4), which is approved for chronic constipation.⁷

Patients with refractory slow-transit constipation may be considered for colectomy with ileorectostomy. However, this procedure is experimental and currently can only be recommended as part of a research protocol. Long-term outcome data are not available.

If slow transit is not present, the patient may have pelvic floor dysfunction, which may respond to pelvic floor exercises or biofeedback.⁸ The value of exercise is not limited to such patients; individuals who report daily physical activity have roughly half the risk for constipation, compared with those who are least active. When higher levels of both activity and fiber intake are paired, the risk for constipation drops roughly 70%, compared with individuals who are least active and eat the least fiber.⁹

The rationale for biofeedback treatment is based on the observation that inappropriate (paradoxical) contraction or a failed relaxation of the puborectal muscle and of the external anal sphincter often occurs during attempts to defecate, and is considered a form of maladaptive learning.¹⁰ Although additional long-term studies are required, the available evidence indicates that biofeedback training provides a significantly higher probability of successful outcome in treatment of functional constipation and functional fecal incontinence than standard medical care.¹¹