EVIDENCE-BASED ANSWER
There is no one best evidence-based treatment for chronic constipation in the elderly. While the most common first-line treatments are dietary fiber and exercise, the evidence is insufficient to support this approach in the geriatric population (strength of recommendation [SOR]: for dietary fiber: A, based on a systematic review; for exercise: SOR: B, based on 1 good- and 1 fair-quality randomized controlled trial [RCT]).
Herbal supplements (such as aloe), alternative treatments (biofeedback), lubricants (mineral oil), and combination laxatives sold in the US have not been sufficiently studied in controlled trials to make a recommendation (SOR: A, based on systematic review).
An abdominal kneading device can be used to treat chronic constipation, but the evidence is limited (SOR: B, based on 1 cohort study.)
Polyethylene glycol has not been studied in the elderly. A newer agent, lubiprostone (Amitiza), appears to be effective for the treatment of chronic constipation for elderly patients (SOR: B, based on subgroup analysis of RCTs.)
Clinical commentary
Is the patient truly constipated?
Mandi Sehgal, MD
Department of Family Medicine/Geriatrics, University of Cincinnati
Many older people feel that if they do not have a bowel movement every day they are constipated. However, constipation is defined as fewer than 3 bowel movements per week. So, the first thing we must do is to confirm that the patient is truly constipated.
Before I start my patients on any medicine, I suggest a trial of increased daily water and fiber intake along with exercise, followed by a trial of stool softeners and stimulant laxatives, if needed. If all of these methods fail, I consider trying polyethylene glycol, which can be titrated to effect. As with all medication use by the elderly, it is important to titrate cautiously (“start low and go slow”) and add other medications only when necessary.
Evidence summary
Few well-designed studies have focused on constipation treatment among the elderly. Our search located 1 systematic review of pharmacologic management, a systematic review of fiber management, 2 RCTs on the effect of exercise, and 1 before-after cohort study on abdominal massage. These studies were all conducted among geriatric patients with constipation. Two high-quality systematic reviews regarding chronic constipation management for adults of all ages included management options not studied in exclusively geriatric populations, such as herbal supplements, biofeedback, tegaserod, and polyethylene glycol.
Laxatives, fiber, and exercise: Studies are inconclusive
Two good-quality systematic reviews looked at 10 RCTs comparing laxatives with placebo, and 10 RCTs comparing 1 laxative with another.1,2 The studies generally had few participants, were of short duration, and were conducted in institutional settings. Most lacked power to make valid conclusions. These studies varied in the reported outcome measures, including stool frequency, stool consistency, straining, decrease in laxative use, and symptom scores. The reviews concluded that the best pharmacologic treatment for chronic constipation in the elderly has not been established.
Five of the higher-quality studies attained statistical significance. They showed a small but significant improvement in bowel movement frequency with a laxative when compared with placebo or another laxative (TABLE). The authors noted that multiple poor-quality studies have shown nonsignificant trends for improved constipation symptoms with laxatives compared with placebo.
Inconsistent findings on fiber. A good-quality systematic review3 of dietary fiber in the treatment of constipation for older patients located 8 moderate- to high-quality studies (6 RCTs and 2 blinded before-after studies), with 269 study participants in institutional settings. Results among studies were inconsistent, casting doubt on the efficacy of fiber treatment for constipation in the institutionalized elder.
Two RCTs4,5 investigating the effect of exercise on 246 institutionalized older patients showed no improvement in constipation. One study was of good quality, reporting adequate power and used an intention-to-treat analysis. The other was of fair quality.