Colonic smooth muscle stimulation via stimulant laxative effect

This entry describes the pharmacological action of stimulant laxatives, which stimulate colonic smooth muscle to increase bowel motility and promote defecation. Stimulant laxatives (including bisacodyl, sodium picosulfate, senna, and cascara) operate by directly activating neural plexuses and smooth muscle in the colon, resulting in both increased muscle contractions and enhanced secretion of water and electrolytes into the lumen. The main therapeutic use is relief of constipation and preparation for bowel procedures. While effective, they may cause various gastrointestinal and electrolyte-related side effects. This is a general physiological mechanism—not a distinct molecular drug target.

Other names

Stimulant laxative effect on colonic motilityColonic motility stimulationStimulation of colonic smooth muscle contraction

Direct stimulation of myenteric and Auerbach plexuses in the colon, leading to increased smooth muscle contractions and intestinal secretions. Irritation of colonic mucosal neurons, resulting in prokinetic and secretory effects. Active metabolites (e.g., BHPM from bisacodyl/SPS, rhein anthrone from senna) stimulate colonic nerves and smooth muscle.