Final answer:
On the second postpartum day, lochia should be pinkish-brown and serous (lochia serosa), indicating a normal transitional stage from the initial red discharge.
Step-by-step explanation:
The nurse should expect the client's lochia on the second postpartum day to be pinkish-brown and serous, which is known as lochia serosa. Lochia serosa is the transition stage following lochia rubra, which is the thick, dark red discharge that occurs for the first 2-3 days after childbirth. The presence of foul-smelling lochia with pus would be abnormal and possibly indicative of an infection. It is not normal for lochia to be absent or minimal at this stage.