causing it to lose its tone. Osmotic Laxatives Movicol: For constipation, take 2-3 sachets daily in divided doses. Only take 1 sachet at a time to see if it helps. You can take this for up to 2 weeks. For faecal impaction– you can take up to 8 sachets per day, for up to 3 days. You should dissolve each sachet in 125mls water. You can add juice to sweeten the taste. Bowel Cleansing Solutions Picolax which you dissolve in water. You can take another sachet 8 hours later. Usually acts within three hours of the first dose. Picolax is only used very occasionally and only under medical advice.