Maralixibat in Patients With Cystic Fibrosis and Constipation

Chronic constipation is common in children with cystic fibrosis (CF), likely due to impaired chloride channel function that reduces intestinal secretions. Standard osmotic laxatives often provide inadequate relief in this population. Maralixibat is an ileal bile acid transporter inhibitor (IBATi) that increases the amount of bile acids reaching the colon. Bile acids can enhance intestinal secretion, reduce transit time, and soften stool. This study will evaluate whether Maralixibat improves stool consistency in children with CF who experience constipation. We will enroll 20 children with CF and constipation, defined as a Bristol Stool Scale score \<4 for at least one week while on a stable laxative regimen. Each participant will receive Maralixibat for two weeks in addition to their usual laxatives. Families will record stool consistency and ease of defecation before and during treatment. The primary objective is to determine whether Maralixibat improves stool consistency to a Bristol Stool Scale score \>4. The secondary objective is to assess changes in ease of defecation using standardized questionnaires.