Physical Properties of Stool

Physical properties of stool are an important part of general stool analysis and help assess the state of the digestive system. The following parameters are evaluated during the examination:

Volume

The normal stool volume is approximately 100–250 grams per day. Increased volume may indicate diarrhea, while decreased volume may indicate constipation or impaired nutrient absorption.

Consistency

Normal stool has a formed or mushy consistency. Liquid stool indicates diarrhea, and overly hard stool indicates constipation. Mucous consistency may indicate inflammatory processes in the intestine.

Color

Typical stool color ranges from yellow to brown. Color changes may signal various disorders:

• Black (tarry) — a sign of bleeding from the upper gastrointestinal tract.
• Pale, clay-colored — possible bile secretion impairment.
• Red — may be a sign of bleeding from the lower intestine.
• Green — often associated with accelerated transit through the intestine or consumption of certain foods.

Odor

Stool has an unpleasant but not sharp odor. A strong foul smell may indicate putrefactive processes or infections in the intestine.

Mucus Presence

Normally, mucus in stool is absent or present in insignificant amounts. Increased mucus may indicate inflammatory bowel diseases, infections, or allergic reactions.

Blood Presence

Normally, blood is absent. Its presence—both visible and occult (detected by special tests)—requires further examination to exclude mucosal damage, tumors, or other pathologies.

Foam

Foam is normally absent in stool. Its appearance may indicate digestive disorders, especially with increased fat or protein content.