http://evolve.elsevier.com/Clayton

Constipation is defined as “a symptom-based disorder of unsatisfactory defecation and is characterized by infrequent stools, difficult stool passage, or both. Difficult stool passage includes straining, a sense of difficulty passing stool, incomplete evacuation, hard/lumpy stools, prolonged time to stool, or need for manual maneuvers to pass stool. Chronic constipation is defined as the presence of these symptoms for at least 3 months” (American College of Gastroenterology Chronic Constipation Task Force, 2005). Chronic constipation afflicts about 15% of North Americans and is more predominant in women, affecting two to three females for every male affected.

Constipation may result from decreased motility of the colon or from retention of feces in the lower colon or rectum. In either case, the longer the feces remain in the colon, the greater the reabsorption of water and the drier the stool becomes. The stool is then more difficult to expel from the anus. Causes of constipation include the following: improper diet, too little residue or too little fluid (e.g., lacking fruits and vegetables or high in constipating foods such as cheese and yogurt); too little fluid intake, especially considering the climate; lack of exercise and sedentary habits (e.g., “couch potato” with remote control); failure to respond to the normal defecation impulses; muscular weakness of the colon; diseases such as anemia and hypothyroidism; frequent use of constipating medications (e.g., morphine, codeine, anticholinergic agents); tumors of the bowel or pressure on the bowel from tumors; and diseases of the rectum.

Occasional constipation is not detrimental to a person’s health, although it can cause a feeling of general discomfort or abdominal fullness, anorexia, and anxiety in some people. Habitual constipation leads to decreased intestinal muscle tone, increased straining at the stool as the person bears down in the attempt to pass the hardened stool, and an increased incidence of hemorrhoids. Using laxatives (medications that stimulate the bowels to evacuate stool) or enemas daily should be avoided because they decrease the muscular tone and mucus production of the rectum and may result in water and electrolyte imbalance. They also become habit-forming; the weakened muscle tone adds to the inability to expel the fecal contents, which leads to the continued use of enemas or laxatives.

Today, many believe that even occasional failure of the bowel to move daily is abnormal and should be treated. Daily bowel movements are frequently not necessary. Many people have “normal” bowel habits even though they have only two or three bowel movements per week. As long as the patient’s health is good and the stool is not hardened or impacted, this schedule is acceptable.