Macrogol (3350) exerts an osmotic action in the gut, which induces a laxative effect. Macrogol (3350) increases the stool volume, which triggers colon motility via neuromuscular pathways. The physiological consequence is an improved propulsive colonic transportation of the soften stools and a facilitation of the defecation. Electrolytes combined with Macrogol (3350) are exchanged across the intestinal barrier (mucosa) with serum electrolytes and excreted without net gain or loss of sodium, potassium and water. Macrogol (3350) is unchanged along the gut. It is virtually unabsorbed from the gastrointestinal tract.