Encopresis Plus?

Dexter is a 12-year-old boy who presents with his maternal grandmother for follow-up to primary care for secondary encopresis. Dexter presented, 18 months ago, with a 3-month history of secondary encopresis. At that time, a comprehensive assessment revealed functional constipation resulting in encopresis. Dexter's symptoms resolved with a combination of medication management and behavioral strategies; laxatives were discontinued 12 months ago.Dexter's grandmother reports that for the past 6 months, her grandson developed encopresis once again. However, she notes that, although Dexter had small-volume episodes of soiling in the past, he is now passing fully formed stools into his underwear. These episodes usually occur once a day, either at home or at school. Frustrated, Dexter's grandmother has transitioned him to adult diapers.Dexter denies hematochezia, pain, dysuria, hematuria, urinary incontinence, dietary changes, or weight loss. He passes soft stool in his underwear once daily without blood or pain. When interviewed alone, Dexter denies drug use, depression, or significant social stressors. Surprisingly, he seems unconcerned about depression, drugs and social stress, and frequently laughs when discussing them. His physical examination, including a rectal examination, is normal.Dexter's medical history is notable for attention-deficit hyperactivity disorder, treated with stimulant medication. He was toilet trained at 3 years without any difficulty. He lives with his grandmother, who is his legal guardian; his mother has chronic mental health problems and substance abuse. Dexter maintains regular contact with his mother and reports that their relationship is positive.Dexter's grandmother is extremely distressed by his current presentation and notably, Dexter is not. What would you do next?