Maralixibat in Patients With Cystic Fibrosis and Constipation

Constipation is a frequent gastrointestinal complication in children with cystic fibrosis (CF). Impaired CFTR-mediated chloride and water secretion leads to dehydrated intestinal contents, slowed transit, and difficulty with stool passage. Despite routine use of osmotic laxatives, many children with CF continue to experience hard stools, abdominal discomfort, and incomplete evacuation, highlighting the need for alternative therapeutic approaches. This study will evaluate the effect of Maralixibat on stool consistency and ease of defecation in children with CF who meet criteria for constipation while on a stable laxative regimen. The study uses a within-subjects design in which each participant serves as their own control. After a baseline observation period, participants will receive Maralixibat for two weeks in addition to their existing constipation management. Families will record stool characteristics and defecation symptoms using standardized tools provided by the study team. Changes in stool consistency and ease of defecation will be assessed by comparing pre-treatment and treatment-period data. The study is designed to generate preliminary evidence regarding the potential utility of IBAT inhibition as an adjunctive therapy for constipation in pediatric CF patients and to inform the feasibility and design of future controlled trials.