Esoteric cure for excess stomach gas

The cure might be not esoteric at all, because gas often comes from things we eat, which are not digestible for us individually. So find out which food is not compatible with you. As a general information, you might find this lecture and the part about James the Elder interesting:
https://glorian.org/learn/courses-and-lectures/the-transformation-of-energy/the-five-causes-of-illness-transcription

The closest chakra to the stomach is the Manipura chakra:
https://glorian.org/learn/glossary/m/manipura