Stool Odor

Stool odor is formed by the breakdown products of proteins, fats, carbohydrates, and intestinal microflora activity. Changes in odor may indicate pathological processes in the gastrointestinal tract.

• Normal (fecal): moderate, typical odor that arises from proper digestion and balanced microflora.
• Strongly unpleasant: may indicate putrefactive processes, increased protein breakdown (putrefactive dyspepsia), microflora imbalance, or bacterial infection.
• Sour: often observed with predominance of fermentative processes, such as dysbiosis, fermentative dyspepsia, or excessive carbohydrate intake.
• Putrid: suggests slowed intestinal motility and fecal stasis, along with active putrefaction of dietary proteins.
• Oily (rancid): may occur with impaired fat digestion (steatorrhea), pancreatic diseases, or biliary tract disorders.
• Odorless: sometimes seen in severe diarrhea or when consuming easily digestible food. Can be normal but requires evaluation of other analysis parameters.

Changes in stool odor are indirect but important diagnostic signs of digestive disorders, bacterial imbalance, and gastrointestinal diseases.