What do you mean by the process of digestion?

$A$ young infant may be feeding entirely on mother's milk which is white in colour,but the stools which the infant passes out are quite yellowish. What is this yellow colour due to?

Where does protein digestion primarily occur?

Bile juice contains no digestive enzymes,yet it is important for digestion. Why?

Correct the statement given below by choosing the right option shown in the bracket against it:
Dipeptides,disaccharides,and glycerides are broken down into simple substances in the region of the small intestine. (jejunum/duodenum).

Which of the following digests proteins into peptides?