Review Article: Do Stimulant Laxatives Damage the Gut? A Critical Analysis of Current Knowledge

Stimulant laxatives are well established as first- or second-line treatments for constipation and although they have a reliable therapeutic effect, alleged safety concerns still exist, particularly with long-term use. The potential harmful effects on the gastrointestinal system (including carcinogenicity) of the long-term use of diphenylmethane [bisacodyl, sodium picosulfate (SPS)] and senna stimulant laxatives were assessed in a comprehensive review of the publications identified in literature searches performed in PubMed and Embase up to and including June 2023. We identified and reviewed 43 publications of interest. While stimulant laxatives at supratherapeutic doses have been shown to cause structural alterations to surface absorptive cells in animals and humans, these effects are reversible and not considered clinically relevant. No formal long-term studies have demonstrated morphological changes in enteric neural elements or intestinal smooth muscle with bisacodyl or SPS in humans. Furthermore, there is no convincing evidence that stimulant laxatives are associated with the development of colon cancer, and in fact, chronic constipation itself has been reported to potentially increase the risk of colon cancer, therefore, the use of stimulant laxatives might reduce this risk. Many studies suggesting a possible harmful effect from laxatives were limited by their failure to consider confounding factors such as concomitant neurological disease, metabolic disorders, and age. These findings highlight the lack of evidence for the harmful effects of laxatives on the colon, and thus, the benefits of treatment with stimulant laxatives, even in the long-term, should be reconsidered for the management of patients with constipation.