gastromancy

noun2

1. •
   Divination by interpreting the sounds and signs of the belly.

   • By Gastromancy, which kind of ventral Fatiloquency was for a long time together used in Ferrara by Lady Giacoma Rodogina, the Eugastrimythian Prophetess. — 1693
2. •
   Divination by noting magical visions in large-bellied glasses, sometimes described as a technique where a child is placed in front of a glass filled with water, the images in the glass then interpreted. Similar to crystallomancy.

   • Diuination generally was done by diuers means..Hydromancy..done either in a glasse bottle full of water, wherein a Childe must looke, (and this is called, Gastromancy of the glasses belly)... — 1610