My feces smells different days before i had nonstop diarrhea took some pills now this why should i see my doctor?

Could be infection: if it is very malodorous and your bowel habits have changed then you should see your physician

Probably not: The smell of feces/stool by itself is never a reason to see your doctor. Stool smells bad because it's full of bacteria, and the bacteria changes over time, and so can the smell, especially after an intestinal infection with diarrhea. If the diarrhea is gone, don't worry about the smell.