Question

A young infant may be feeding entirely on mother's milk, which is white in colour but the stool, which the infant passes out is quite yellowish. What is the reason for this yellow colour?

• A. Intestinal juice
• B. Bile pigments passed through bile
• C. Undigested milk protein casein
• D. Pancreatic juice poured into duodenum

Answer 1

Answer: (B)

Bile pigments passed through bile

A bile pigment called stercobilin is responsible for the brown colour of human faeces. These pigments are formed as a result of the breakdown of the heme of hemoglobin found in erythrocytes. Macrophages break the heme into biliverdin, which rapidly reduces to free bilirubin. This bilirubin is further converted to colourless urobilinogen and finally oxidized to stercobilin. Stercobilin is then excreted in the faeces.

So, the correct answer is B.