THE ANTIMETABOLITE, fluorouracil, has been the chemotherapeutic agent of choice in the treatment of advanced cancers of the gastrointestinal tract during recent years. The use of this drug is based on the suggestion that uracil may serve preferentially as a building block for nucleic acid biosynthesis in some tumors. It is believed that fluorouracil or its biologic metabolites block the enzyme thymidylate synthetase, and interfere with the synthesis of deoxyribonucleic acid and, to a lesser extent, the synthesis of ribonucleic acid. The inhibition of DNA and RNA results in unbalanced growth and the death of a cell.1,2 Many studies have been undertaken with fluorouracil in the treatment of various cancers and numerous methods of administration of the agent have been tried.3,4Its most common method of administration at present has been the intravenous route, but even so some controversy has existed pertaining to various methods of injection, ie,