Bowel Retraining for Constipation

The surgeon's first priority when faced with a patient complaining of constipation is to eliminate mechanical obstruction as the cause of the constipation. A complete history and physical examination should be performed. The history needs to focus on multiple factors, but specific attention should be given to the patient's medications as well as their diet and exercise regimen. If mechanical obstruction has not been ruled out before evaluation of the patient, this should be done either by colonoscopy or barium enema.

Diets low in fiber coupled with poor bowel habits are common causes of constipation. Management requires reassurance and simple guidance. Patients, especially those with fast-paced and stressful lifestyles, should be advised not to ignore the call to stool because it can lead to stasis and impaction. Regular exercise (e.g., a walk every morning) promotes regularity. Narcotics, diuretics, calcium channel blockers, antidepressants, and irritant laxatives may all result in constipation through different mechanisms. Fortunately, the effects of most of these agents are reversible, and discontinuing the medication usually results in cessation of the constipation. Meal patterns such as meal omission, fast foods, ingestion of large amounts of constipating foods, and inadequate intake of fluids should be recognized and modified. These changes, with the addition of fiber, aid to retrain the bowel to promote regularity and homeostasis as well as deter the onset of disease such as diverticulosis and cancer.

The addition of a fiber supplement to the diet is often therapeutic in the management of constipation. Inadequate fiber intake is a consequence of industrialization and results in small, hardened stools, poor peristalsis, and ultimately, constipation. The usual daily fiber intake by members of Western society is 10 to 14g. The recommended daily fiber intake is 25 to 30 g of insoluble fiber with a maximum of 36g in a 24-hour period. Insoluble fiber may be found in the form of psyllium or other vegetable fiber. Psyllium (3 g per os once or twice a day) is usually an adequate supplement to restore regularity or normalcy to most diets and bowel patterns. Patients are instructed to drink at least six, 8-oz glasses of water a day when taking a fiber supplement to avoid concretions. The majority of patients with complaints of constipation, inadequate rectal emptying, rectal pressure, straining, hard stools, and irregularity will respond to fiber supplementation with adequate fiber intake and need no further treatment. Thus, a fiber trial is not only a test but also a treatment and should be the initial therapy before embarking on an otherwise costly work-up yielding a diagnosis that may be amenable to fiber supplementation.

Despite counseling patients on eating properly, ingesting additional fiber, engaging in regular exercise, and not ignoring the urge to defecate, the addition of laxatives for the persistently constipated patient may be needed, especially in the elderly (Table 12-3.1). Laxatives are divided into two classes: stimulants and mechanical cleansers. Stimulants act to irritate the intestinal lining resulting in increased water, electrolyte, and mucus secretion and con-

Table 12-3.1. Frequently used bowel agents for constipation

Agent Type

Name

Dosage

Fiber

Psyllium seed

Metamucil,

1-2 tsp q.d.-t.i.d.

preparations

Konsyl

Synthetic

Citrucel

1 tbsp PO q.d.-t.i.d.

methylcellulose

Mechanical cleansers

Saline laxatives

Magnesium salt

Magnesium citrate

120-240 mL PO q.d.

Phosphate salt

Fleets Phospho-

30-45mL PO q.d.

Soda

Polyethylene

GoLYTELY

12oz PO q.d.

glycol

Miralax

17g PO q.d.

Mineral oil

15-45mL PO q.d.

Lactulose

15-30mL PO q.d.-t.i.d.

Stimulants

Senna

Senokot

2-4 tabs PO q.d.-t.i.d.

Biscodyl

Dulcolax

10mg PO or PR q.d.

Prokinetic agents

Metoclopramide

Reglan

5-10 mg PO q.a.c. and q.h.s.

Cisapride

Propulsid

10-20mg PO q.i.d. (restricted

access in U.S.)

Erythromycin base

20 mg/kg/d PO divided t.i.d.-q.i.d.

Tegaserod

Zelnorm

6mg PO b.i.d.for 4-8wk

q.d., every day; t.i.d., three times a day; PO,

)er os; q.a.c., before each meal; q.h.s.,

before bedtime; q.i.d.,four times a day; b.i.d., twice a day

sequent rapid evacuation. These agents are useful in the treatment of acute constipation, but long-term use should be discouraged because it can lead to a poorly functioning large intestine. Mechanical cleansers exert their effect through osmotic activity of poorly absorbed salts (magnesium or phosphate salts), disaccharides (lactulose), or electrolyte solutions (polyethylene glycol, also known as GoLYTELY or Miralax). The net result is increased peristalsis and evacuation of large amounts of watery stools. Liquid petrolatum (mineral oil) retards the absorption of water from the stool and thus softens and bulks fecal material. These substances can be safe adjuncts to a regular regimen for both short- and long-term use in bowel retraining for severe constipation; however, long-term use of mineral oil may lead to anal stenosis or stricture and should be avoided. A daily 12-oz glass of polyethylene glycol (GoLYTELY, Miralax) or lactulose may be used to propel colonic contents and is particularly effective in intractable constipation from colonic inertia. However, caution must be taken to avoid adverse effects that may result from over-consumption such as electrolyte abnormalities, vitamin deficiencies, dehydration, and malabsorption.

Regular use of suppositories and enemas are useful in evacuating the lower bowel. Various types of suppositories are available and primarily work through a reflex mechanism. Enemas work by causing distention, increasing stool volume through an osmotic effect, and direct irrigation of the lower bowel. Suppositories have the advantage of being easier to administer; however, both can safely be used as part of a regular bowel routine in those patients who require assistance with scheduled bowel evacuation. For cases of intractable constipation and the inability to evacuate, the performance of antegrade continent enemas (ACE) has been shown to be effective in bowel retraining in patients who have traditionally relied on laxatives, enemas, digital stimulation, and manual disimpaction.4 Several minimal techniques have been developed (ACE procedures) to facilitate the administration of antegrade enemas. Most involve the creation of a continent colonic conduit consisting of either an appendicocecostomy or button cecostomy forming a channel that can be easily catheterized to perform regular colonic irrigations. More recently, the laparoscopic ACE (LACE) procedure has been described, which offers the potential advantages of a shorter hospital stay, faster recovery, less pain, and better cosmesis.

Current management of constipation has focused on the use of prokinetic drugs that enhance propulsive activity rather than acting as intestinal irritants. The function of these drugs is primarily to augment the intrinsic motor function of the gut. They are particularly efficacious in colonic inertia in which constipation is believed to result from the degeneration of colonic nerve fibers or abnormal terminal synapse function in the colon. Reglan, cisapride, and erythromycin may be used as part of a comprehensive bowel regimen in this condition to promote motility and stimulate peristaltic activity. The most recent promotility agent is tegaserod (Zelnorm), a 5-HT4 receptor partial agonist, which has been shown to successfully relieve abdominal pain and constipation associated with irritable bowel syndrome by aiding in gastrointestinal motility and modulating visceral sensation.

Along with dietary changes and pharmacotherapies, biofeedback is a viable option for the treatment of constipation. Biofeedback refers to therapy in which patients are trained to be more aware of and responsive to their bowels. It has been increasingly used in the management of functional pelvic floor disorders, such as constipation from obstructed defecation, fecal incontinence, and rectal pain. In patients with constipation secondary to obstructed defecation, biofeedback is used to heighten the patient's awareness of the sphincters and levator muscles to retrain these muscles to consciously relax during the act of defecation. One cause of pelvic outlet obstruction occurs as a result of nonrelaxation of the puborectalis muscles. This condition may be related to significant psychosocial stresses that may cause the patient to alter their normal defecatory patterns.

Biofeedback facilitates bowel retraining through counseling and audio or visual feedback that allows the patient to properly relax their puborectalis muscles resulting in defecation. Through the use of manometry, balloon defecography, surface electromyography (EMG), or intraanal EMG, the patient is shown the effects of his or her own squeeze efforts and the resultant muscular actions of the external sphincter and puborectalis complex. This rein forces to the patient appropriate behavior and modifies errors in the muscular activity. The goal is to retrain the pelvic musculature to elicit the appropriate response in performing the actions related to defecation. Success rates reported in the literature are variable although it seems to be more successful using EMG feedback as opposed to balloon expulsion exercises. Reports of success with biofeedback for constipation vary between 60% to 80%. At our institution, EMG-based biofeedback for patients with constipation is successful approximately 60% of the time.

Bowel retraining in constipation involves a multimodal regimen that can be tailored to the degree of the patient's condition. Patients who are unresponsive to simple dietary modifications, fiber therapy, or medical interventions may require scheduled laxatives or colonic irrigations. Patients with obstructed defecation may respond to a trial of biofeedback in which behavioral therapy is used to modify and retrain the muscles of the pelvic floor in coordinating defecation. Patients who do not respond to medical management of their constipation and who may be surgical candidates should undergo further work-up including colonic transit studies, defecography, possible EMG, and small bowel transit studies. These tests may then be interpreted with possible surgical intervention, if warranted.

Constipation Prescription

Constipation Prescription

Did you ever think feeling angry and irritable could be a symptom of constipation? A horrible fullness and pressing sharp pains against the bladders can’t help but affect your mood. Sometimes you just want everyone to leave you alone and sleep to escape the pain. It is virtually impossible to be constipated and keep a sunny disposition. Follow the steps in this guide to alleviate constipation and lead a happier healthy life.

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