This document presents a comparative study on the pathogenesis (samprapti) of udara roga (abdominal diseases) according to the three major classical Ayurvedic texts - Bruhatrayi. It begins with an introduction on udara roga and mentions it is considered one of the eight major disorders. It then discusses the references of udara roga in Bruhatrayi and Laghutrayi texts. Several sections provide details on the general causes (nidanas), premonitory symptoms (poorvaroopa), common signs/symptoms (lakshanas) and pathogenesis of udara roga according to Charaka, Sushruta and Vagbhata. It also compares