Vomit causes not only an unwanted odor but also a yellow bile stain that can be tough to remove. For this purpose, you can use either white vinegar or hydrogen peroxide. Before applying these solutions, dilute them with water. Apply the solution to the top of the stain and blot the area with a clean towel or paper towels. Don’t mix hydrogen peroxide with white vinegar, though, because you can cause damage to the carpet. If the stain is persistent, you can repeat the same process several times until it’s gone.