The invention relates to fatty acid stimulation of rectal mucosa initiating the process of defecation, acting as a laxative. Furthermore, the invention relates to the usage of free fatty acids, fatty acid mixtures and fatty acid extracts from marine lipids in pharmaceutical formulations such as suppositories, ointments, tablets and gelatin capsules for treatment and prevention of multiple disorders like constipation, hemorrhoids, bacterial infections (e.g. helicobacter pylori), viral infections (e.g. herpes simplex virus infections) and inflammations, as well as against fissura ani and pruritus ani.