From wiki:
The gas released during a flatus event frequently has an unpleasant odor. For many years, this was thought to be due to skatole and indole, which are byproducts of the digestion of meat. However, gas chromatography testing in 1984 revealed that sulfur-containing compounds, such as methanethiol, hydrogen sulfide (rotten egg smell) and dimethyl sulfide, were also[2] responsible for the smell.[3]

The incidence of odoriferous compounds in flatulence emissions increases from herbivores, such as cattle, through omnivores to carnivorous species[citation needed]. Such odor can also be caused by the presence of large numbers of microflora bacteria and/or the presence of feces in the rectum.
skatole - "It occurs naturally in feces (it is produced from tryptophan in the mammalian digestive tract)", same with indole
methanethiol - "It occurs naturally in certain foods, such as some nuts and cheese. It is also one of the main chemicals responsible for bad breath and the smell of flatus."

If you have cut back on meat, nuts, and cheese, that may explain it.