Gas is a normal byproduct of digestion, and most people pass gas 13-21 times a day. Some of the most common causes of smelly farts are the rapid breakdown of bacteria, food intolerances, constipation, ...
Pepto Bismol can also reduce odor. The article further advises eating slowly, limiting gas-producing foods, avoiding gum and carbonated drinks, and quitting smoking to manage excessive flatulence.