Movicol Plain Powder Sachets are a laxative for the treatment of constipation in adults, adolescents & the elderly. They are not recommended for children below the age of 12 years. Movicol Powder is an oral treatment that helps you to have a comfortable bowel movement, even if you have been constipates for a long time. Movicol can also work for very bad constipation called faecal impaction.