A 20-day-old male infant is brought to the emergency department with a complaint of extreme fussiness. His parents think he has abdominal pain and they reported episodes of intractable continuous crying for 3-4 hours for four days, usually in the evenings. They have tried feeding, rocking, and changing the diaper but nothing relieved the crying. He is currently been feeding a cow's milk formula fortified with iron and with no complaints of vomiting or diarrhea. History He was born at term with no prenatal problems or infection.
Mother did not use any illicit drugs. He has been having good weight gain and no fussiness until 4 days ago. There is no history of vomiting, apnea, constipation, fever, seizure, or trauma. He has been behaving normally between daily episodes of fussiness. Examination Pulse: 130 beats/minute, RR: 32 breaths per minute, BP 80/55 mm Hg, oxygen saturation: 100% in…
