What do you suggest if my fart sometimes smells like leaking cooking gas. why?

Flatulence problem?: Flatulence neither localizes your problem to small or large bowel, nor indicates severity or cause. You have described a gut that may be dysfunctional due to infection, sibo, motility problems, inflammation, ibs, ischemic disease, maldigestion, sphincter problem, or food intolerance. Could consider a course of probiotics &/or diet exclusions, but recommend evaluation if this is significant change.