Constipation affects many individuals in the United States. The prevalence of constipation symptoms ranges from 12-30% with a greater prevalence in the elderly. Although many constipated individuals ignore their symptoms or treat themselves by modifying their diet or using over-the-counter remedies, it still accounts for at least 2.5 million physician visits per year. Constipation can be defined as two or more of the following symptoms for at least 3 months:

• Straining more than 25% of the time
• Hard stools more than 25% of the time
• Incomplete evacuation more than 25% of the time
• <3 bowel movements in 1 week

In general, the causes of constipation have been separated into three groups:

• Slowed Colon Transit (slow movement of stool through the colon)
• Pelvic Floor Dysfunction (abnormal coor- dination of pelvic floor muscles result- ing in difficulty emptying stool effectively)
• Irritable Bowel Syndrome (abdominal pain/ discomfort associated with a change in bowel habits)

If you suffer from intractable constipation or if you recently developed constipation, your doctor can order several diagnostic tests which may be helpful in determining the cause of constipation symptoms. These include colonoscopy, sigmoidoscopy, and barium enema which can show anatomic lesions of the colon, such as cancer and polyps. Other tests include anorectal manometry, colon transit study, and defecogram which examine the function of the colon and rectum.

The UCLA/CURE Neuroenteric Disease Program studied 131 constipated patients to determine if there are bowel symptoms and physiologic findings of the colon and rectum function which may be useful in the identification and understanding of these three constipation groups. Patients with slow transit constipation rated their gastrointestinal problem as more severe than the other two groups. In addition, these patients tended to have fewer bowel movements which averaged fewer than 3 per week and a rare urge to have a bowel movement. Patients with pelvic floor dysfunction did not have specific symptoms or detectable abnormalities in physiologic testing. Constipated patients with typical irritable bowel syndrome and an increased sensitivity to balloon inflation in the rectum more often reported belly pain, bloating, visible abdominal distension and chest pain. These findings may have significant implications for the cost-effective management of constipation symptoms.

The treatment of constipation includes fiber supplementation, exercise, fluid intake and avoidance of medications which worsen symptoms of constipation. Patients with slow transit constipation who fail these measures can be treated with laxatives. A small number of selected patients with refractory slow transit constipation may benefit from total colectomy. Individuals with pelvic floor dysfunction may benefit from biofeedback training which teaches a person to control the function of the pelvic floor muscles. If patients have constipation-predominant irritable bowel syndrome and pain is a predominant symptom, they may be treated with medications such as amitryptiline in addition to laxatives.

There are several promising new medications which appear to be effective in the treatment of constipation symptoms. Preliminary studies have shown that two of these medications act on the serotonin system and can improve abdominal pain, stool frequency and form, and straining. The Neuroenteric Disease Program will soon be participating in a multi-center study evaluating the effect of a new medication for constipation. This medication will potentially treat symptoms of constipation by improving the movement of stool through the bowel through its action on the nerves of the bowel. If you are interested in participating or learning more about clinical research studies for constipation, please call (310) 312-9381.