Review Question - QID 109282

A 4-day-old boy presents to the pediatrician with his mother for his 1st well visit. The patient was born at 36 weeks gestation to a 26-year-old primigravid mother via cesarean section for cervical incompetence. The patient required no resuscitation at birth and both mother and child were discharged from the hospital at 2 days of life. The patient has been exclusively breastfed since birth, and his mother reports that he feeds for 20-30 minutes every 2 hours. The patient urinates 7 times per day and has begun passing 2-3 stools per day that his mother describes as “grainy” and the color of “mustard.” His birth weight was 3670 g (8 lb 1 oz), and his current weight is 3487 (7 lb 11 oz). His temperature is 97.1°F (36.2°C), blood pressure is 57/42 mmHg, pulse is 140/min, and respirations are 38/min. On physical exam, the patient’s anterior fontanelle is soft and flat, and his eyes are moderately icteric. His abdomen is soft and non-distended. The patient has the physical exam finding seen in Figure A. His diaper can be seen in Figure B. Laboratory studies reveal the following:

Total bilirubin: 13 mg/dL
Conjugated bilirubin: 0.6 mg/dL

Which of the following is the most appropriate next step in management?