Constipation has many definitions and is often described differently depending on the population queried. Physicians may define constipation as a reduction in the frequency of bowel movements to fewer than three times per week while patients identify more with the symptoms associated with constipation such as difficulty passing stool, hard stool consistency, feelings of abdominal cramping, and feelings of incomplete stool passage. Causes of constipation may be primary (idiopathic) or secondary to other factors such as diet, medication, or medical conditions. Constipation can affect anyone as a minor annoyance but up to a quarter of the population experiences it chronically or severely. It can substantially affect quality of life and be debilitating. It is estimated that between 2% to 27% of the population are affected depending upon the definition of constipation used.
Several treatment options are available and include dietary or bulking agents, osmotic or stimulant laxatives, stool softeners, and 5-HT4 agonists. Bulking agents include soluble fibre (i.e. psyllium, ispaghula) and insoluble fibre (i.e. wheat bran), which, when taken with water, increase stool bulk and stool frequency. Osmotic laxatives (i.e. lactulose, polyethylene glycol [PEG], macrogol, milk of magnesia), are poorly absorbed by the gut and act as hyperosmolar agents, increasing the water content of stool and making the stool softer and easier to pass. Stimulant laxatives (i.e. sennosides, bisacodyl, sodium picosulfate) act on the intestinal mucosa, increasing water and electrolyte secretion and stimulating peristalsis. Stool softeners (i.e. docusate sodium or calcium) are thought to facilitate the mixing of aqueous and fatty substances and thereby soften the stool. The 5-HT4 agonists (i.e. prucalopride) stimulate peristalsis which increases colonic motility in individuals with non-neurogenic causes of constipation.
Considering the different causes and patient populations that may experience constipation, there are questions with regards to the efficacy and safety of the treatments available. A recent Rapid Review concluded there was a paucity of good quality of evidence to support the use of stool softeners for the management or prevention of constipation in adults in a hospital or long-term care setting. Docusate appeared to be no more effective than placebo for increasing stool frequency or softening stools and did not lessen symptoms associated with constipation. The purpose of this report is to review the available evidence for the safety and efficacy of stool softeners, laxatives, bulking agents and 5-HT4 agonists for the management of constipation in adults and children.
Disclaimer: The Rapid Response Service is an information service for those involved in planning and providing health care in Canada. Rapid responses are based on a limited literature search and are not comprehensive, systematic reviews. The intent is to provide a list of sources of the best evidence on the topic that CADTH could identify using all reasonable efforts within the time allowed. Rapid responses should be considered along with other types of information and health care considerations. The information included in this response is not intended to replace professional medical advice, nor should it be construed as a recommendation for or against the use of a particular health technology. Readers are also cautioned that a lack of good quality evidence does not necessarily mean a lack of effectiveness particularly in the case of new and emerging health technologies, for which little information can be found, but which may in future prove to be effective. While CADTH has taken care in the preparation of the report to ensure that its contents are accurate, complete and up to date, CADTH does not make any guarantee to that effect. CADTH is not liable for any loss or damages resulting from use of the information in the report.
