Hi, It seems you are having fatty diarrhea caused by excess fat in stools, or an oily anal leakage. Anal oily leakage can also be due to keriorrhea (orange oily anal leakage caused by high levels of escolar and oilfish in the diet).The escolar also known as snake mackerel,a species of fish is found in deep tropical and temperate waters around the world. Escolar s wax ester content can cause keriorrhea . Leakage of loose oily faeces can lead to itching around the anus, because prolonged contact with substances in the faeces causes irritation of the skin . Pre-moistened toilet tissues (wet-wipes), bought from chemists and supermarkets, can sometimes cause anal itching. The reason is probably perfume, alcohol or a preservative in the wipes. Threadworms (pinworms) can cause anal pruritus. Sexually transmitted and other infections are what many people worry about, but are not usually the reason. Genital herpes (caused by herpes virus) can also infect the anus, and causes itching just before the sores appear and also during the healing stage but it will not cause oily diarrhoea. Regards Dr. T.K. Biswas M.D. Mumbai