Tony is a five and a half-year-old boy who has been a patient in your primary care practice since he was adopted at birth. He has been treated by a child and adolescent psychiatrist for behavioral concerns starting at age 3 years and has been diagnosed with autism spectrum disorder, attention-deficit/hyperactivity disorder (ADHD) combined type, anxiety disorder, and insomnia. He presents today with complaints of repeated emesis and refusal to eat or drink over the past 2 weeks and is now dehydrated. Tony was born at 30 weeks' gestational age by vaginal delivery with a birth weight of 4lbs 15oz and was described as minimally responsive at birth. There was known prenatal exposure to tobacco and methamphetamine and inadequate prenatal care. The maternal history is notable for a reported diagnosis of bipolar affective disorder, prostitution, and being unhoused at the time of delivery. Tony received antibiotics after delivery for presumed newborn infections. As an infant, he had kidney reflux, low serum ferritin, insomnia, and failure to thrive. Regarding developmental milestones, Tony was sitting up at 7 months, walking at 14 months, talking at 18 months, and speaking in full sentences by 24 months. When he presented to the psychiatric service at age 3 years, behavioral problems included irritability with destructive rages, excessive fears, separation anxiety, hyperactivity, and impulsivity with a lack of awareness of danger to the extent that he required a safety harness when in public and security locks in the home because of repeated elopements. Tony also had at the time of his initial presentation significant defiance, extreme tantrums, violent aggressive outbursts, cognitive rigidity, repetitive behaviors, resistance to change, frequent nondirected vocalizations, and self-injurious behaviors including slapping himself on the head and biting of his hands and feet. Review of systems includes complaints of frequent abdominal and neck pain, persistent insomnia, night terrors, restrictive eating habits with poor weight gain, and reduced sensitivity to pain. Treatment history included gabapentin and subsequently divalproex for seizure-like episodes (despite negative EEG) described as frequent staring spells with repetitive biting of his lips. Psychotropic medications were risperidone for irritability associated with autism and clonidine extended release for ADHD. He also took melatonin for sleep. During his well-child check at the age of 5 years, Tony is making good progress from a developmental standpoint, has age-appropriate expressive and receptive language skills, is fluent in both English and Spanish, is able to recite the alphabet, counts to 20, has learned to swim, and is demonstrating interest in planets and astrology. He is reported to have a secure attachment to his adoptive parents and is described as emotionally sensitive, caring, kind, considerate, and empathetic. He has good eye contact and can read facial expressions. He is affectionate and protective of his infant sibling, his biological sister, who is also adopted by his parents and now living in the home. Tony made an excellent adjustment to the start of kindergarten and up until this point was responding positively to his psychotropic medication regimen. But then at age five and a half, Tony experienced sudden and unexplained behavioral worsening, which was followed by the onset of recurrent vomiting and refusal to eat or drink. Comprehensive medical workup including upper endoscopy and biopsy resulted in a diagnosis of eosinophilic esophagitis (EoE). What would be your next step?