Pharmacological Rectal Stimulants
Pharmacological rectal stimulants (suppositories and enemas) are a common component of a successful bowel management program, used by up to 60% of individuals with UMN bowel dysfunction (Coggrave et al. 2009). The two most commonly used are the glycerin suppository, which provides a mild local stimulus and lubrication, and the bisacodyl (dulcolax) suppository, which provides a dose of stimulant laxative directly to the colonic mucosa producing peristalsis throughout the colon. Other options include sodium hydrogen carbonate suppositories, sodium citrate and glycerol micro-enema and docusate sodium micro-enema.
Discussion
Pharmacological rectal agents (suppositories or enemas) are commonly used by individuals with SCI to stimulate reflex evacuation at the time chosen for bowel care. They are an essential element of a bowel program for many individuals with upper motor neuron bowel though there is little evidence to support most of the suppositories and enemas used. However, the effectiveness of the hydrogenated vegetable oil-based bisacodyl suppositories compared to the polyethylene glycol-based suppositories has been examined. The total bowel care time with the polyethylene glycol-based suppository is significantly less (Stiens et al. 1998; Frisbie 1997; Dunn & Galka 1994) compared to hydrogenated vegetable oil based suppository. House and Stiens (1997) compared the effectiveness of hydrogenated vegetable-based, polyethylene glycol-based and docusate glycerin (mini-enema) in subjects with upper motor neuron lesions. Results showed a significant decrease in bowel care time using the polyethylene glycol-based suppository and the mini-enema as compared with the hydrogenated vegetable oil-based suppositories. Amir et al. (1998) found in a cohort of seven individuals with SCI that docusate sodium mini enema scored best in neurogenic bowel symptom reduction followed by, in descending order of efficacy, mineral oil enema, bisacodyl suppositories and glycerin suppositories.
Conclusion
There is level 1b evidence (from 1 RCT: House & Stiens 1997) to support polyethylene glycol-based suppositories for bowel management. There is a clinically significant decrease in the amount of nursing time for persons requiring assistance and less time performing bowel care for the independent individual.