Quanji tongxuan lun 痊驥通玄論 "Expertise in horse medicine", also called Yuan Bian guangou ji 元卞管句集, Majing tongxuan fang lun 馬經通玄方論 or Simu majing quanji tongxuan lun 司牧馬經痊驥通玄論 (during the mid-Qing period, the character 玄 was replaced by 元 to avoid the tabooed personal name of the Kangxi emperor 康熙帝, Xuanye 玄燁), is a book on horse medicine written by "Clerk" (guangou 管句) Bian 卞管句 during the Yuan period 元 (1279-1368). "Clerk" Bian might be identical to Bian Bao 卞寶, who is mentioned in the book Yuan-Heng liaoma ji 元亨療馬集 and hailed from Dongyuan 東原 (todays Ningyang 寧陽, Shandong).
The book consists of three parts, namely 39 theories of "penetrating the mysteries of healing horses" (Quanji tongxuan sanshijiu lun 痊驥通玄三十九論), 46 explanations (Quanji tongxuan sishiliu shuo 痊驥通玄四十六說), and annotated prescriptions for medical decoctions (Quanji tongxuan lun zhujie tangtou 痊驥通玄論注解湯頭). In this form, the book provides thorough information on theory, methods, prescriptions and materia medica for equine medicine, and adds to the knowledge provided in the Tang-period 唐 (618-907) book Simu anji ji 司牧安驥集.
The exact year of the first publication of the book is unknown. The earliest surviving copy from 1506 is a reprint. Substantial parts of the book are quoted in Yang Shiqiao's 楊時喬 (1531-1609) Mashu 馬書 (ch. 11), even if in abbreviated shape. The reconstruction of Bian's book by Cui Diseng 崔滌僧 (1885-1966) in 1959 therefore made use of the Mashu chapter. Other sources for this reconstruction was a copy owned by the Yan family 閻氏 of Chang'an 長安 (Xi'an 西安, Shaanxi). The result of Cui's work is the edition Jiaozheng zengbu Quanji tongxuan lun 校正增補痊驥通玄論.
The largest part of the "Thirty-nine theories" deals with the anatomy, physiology and pathology of the stomach and other intestines, the etiology, symptoms and treatment methods of various disorders in the behaviour of horses (qiwo 起臥 "standing and lying"); especially the diagnosis and treatment method by inserting the arm into the rectum is very detailed. The last six treatises dealt with eye diseases, pain theory, three throat syndromes and fifty-four reasons for death.
The first fifteen of the "Forty-six explanations" deal with the physiology, pathology and symptoms of the viscera; the next decade of explanations is about the "ten poisons" (shi du 十毒) in sores and boils; and the last twenty-one explanations talk mainly about diagnosis and treatment methods and the ways of watering and feeding. The section on decoctions contains 113 different prescriptions, many of which are reasonable, simple and practical.