Described are devices, methods, and systems useful in the treatment of fistulae, and in certain embodiments those having openings extending into the alimentary canal, such as anorectal fistulae. Illustratively, an anorectal fistula can be treated by placing a volumetric construct within the primary opening of the fistula. In certain embodiments, the volumetric construct can include a rolled remodelable material processed to form a substantially unitary body. Advantageous such remodelable materials can include collagenous extracellular matrix materials, such as small intestine submucosa.