Use of laxatives in institutions for the mentally retarded

To study, in institutionalized mentally retarded patients, the prevalence of regular laxative use, and to identify its correlates.

Twenty-one of the 22 institutions for the mentally retarded in Flanders (Belgium) provided the setting for the study, which included a population of 3712 residents with an IQ of < 50. This was a descriptive cross-sectional study of a random sample of 20 patients per institution, consisting of a structured interview of the personnel responsible for daily care of the selected patients. The study population consisted of 420 mentally retarded patients. Their median age was 29 years (range 2-72 years). Twenty-six percent of patients had an IQ of 35-49, 40% an IQ of 20-34 and 34% an IQ of <20. Sixteen percent of the patients were non-ambulant.

Regular laxative use was found in 26.4% (111/420) of the residents. In addition, occasional laxative use was found in 2% (10/420) of the residents. Oral laxatives were used daily by 13% (56/420) and oral laxatives daily in combination with enemas were used by 9% (39/420). Enemas but no oral laxatives were used by 3% (11/420); manual evacuation in combination with oral laxatives and enemas was used by 1% (5/420). Seventy-eight percent (78/100) of the oral laxative users used them for more than 1 year. Seventy-one percent (71/100) used one laxative, 23% two and 6% three. Thirty different brands of oral laxatives were used. Sixty-seven percent (67/100) used osmotic laxatives alone or in combination, 30% used stimulant laxatives, 19% used bulk forming laxatives and 19% mineral oil. Oral laxatives were always prescribed by attending physicians, while enemas were also initiated by nurses in 35% (18/52). Laxative use was positively and independently correlated with female gender, with being non-ambulant, with oral motor dysfunction and with the use of medication other than laxatives. It did not correlate with age. Within the institutions, laxative use varied from one to 15 users out of the 20 randomly selected patients (median 4/20).

Laxative use is frequent in institutions for the mentally retarded, with a large inter-institution variation, indicating that constipation is an important problem and underlining the need for research into cost-effective treatment.