Movicol typically takes about 12 to 72 hours (1 to 3 days) to work, with most people experiencing a bowel movement within one to two days after taking the first dose. The exact timing can vary based on individual response, severity of constipation, and whether it is used for occasional or chronic relief. It works by softening the stool and drawing water into the bowel to make stools easier to pass, usually resulting in relief within 24 to 48 hours for most users. If there is no improvement after a couple of days, dosage adjustments or consulting a healthcare professional may be necessary.