sometimes poop smells bad

especially when you eat junk food

feces normally have an unpleasant smell. foul-smelling stools have an unusually strong, putrid smell.
in many cases, foul-smelling stools occur due to the foods people eat and the bacteria present in their colon. however, foul-smelling stools can also indicate a serious health problem. diarrhea, bloating, or flatulence may occur with foul-smelling stools. these stools are often soft or runny.