From the Guidelines
Stimulant laxatives, such as senna or bisacodyl, can be used to treat slow transit constipation, but they should be added to an osmotic laxative if there is an inadequate response, as stated in the 2020 Gut journal study 1. When considering the use of stimulant laxatives for slow transit constipation, it's essential to understand their mechanism of action and potential side effects. These medications increase intestinal motility and can cause abdominal cramp; therefore, they should be avoided in intestinal obstruction 1. Some key points to consider when using stimulant laxatives for slow transit constipation include:
- They should be used cautiously and typically not as first-line therapy for long-term management
- Excessive use can cause diarrhea and hypokalaemia
- The anthraquinone laxatives (senna, dantron, cascara) are converted in the intestine to active sennosides, which may function by stimulating the myenteric plexus in the colon and also by inhibiting colonic water absorption
- Poorly absorbed diphenylmethane derivatives (bisacodyl, phenolphthalein, sodium picosulfate) stimulate sensory nerves in the proximal colon and increase sodium and water movement into the colonic lumen For slow transit constipation, it's better to start with lifestyle modifications (increased fiber, hydration, physical activity) and osmotic laxatives (like polyethylene glycol) before trying stimulants, as recommended in the study 1. If slow transit constipation is severe or chronic, medical evaluation is important to rule out underlying conditions and develop a comprehensive treatment plan that might include judicious use of stimulant laxatives as part of a broader approach.
From the Research
Effectiveness of Stimulant Laxatives in Treating Slow Transit Constipation
- Stimulant laxatives, such as senna or bisacodyl, are considered first-line therapy for slow transit constipation, although studies often show a diminished colonic motor response to such agents 2.
- The use of stimulant laxatives can increase stool frequency and improve stool consistency in patients with slow transit constipation 3.
- However, laxative use has no apparent effect on pain or bloating or upon a patient's feeling of complete evacuation 3.
Safety and Long-Term Use of Stimulant Laxatives
- There is no evidence to suggest that chronic use of stimulant laxatives is harmful if they are used two to three times per week 2.
- However, the evidence base does not support the use of stimulant laxatives for more than four weeks, and longer-term studies are warranted to investigate their effects and safety 4.
- Available stimulant laxatives, such as senna and bisacodyl, are both safe and effective when used long-term, but the choice of treatment should be based on cost as well as efficacy 5.
Alternative Treatment Options
- Other treatment options for slow transit constipation include polyethylene glycol, misoprostol, colchicine, and biofeedback therapy 2, 6.
- Subtotal colectomy with ileorectal anastomosis may be effective in patients with colonic inertia, normal anorectal function, and lack of evidence of generalized intestinal dysmotility 2, 6.