CosmoCol is a laxative used for the treatment of long term (chronic) constipation and faecal impaction (persistent constipation, where a large volume of stools cause a blockage of the rectum and / or colon). It is not recommended for children below 12 years of age. Macrogol 3350 makes your faeces softer and easier to pass, giving you relief from constipation. The electrolytes (salts) help to maintain your body’s normal levels of sodium, potassium and water while you are being treated for constipation.