A diverticular remodeling technique comprises the introduction of a remodeling agent into the diverticulum to promote permanent closure of the diverticular sac. In disclosed exemplary embodiments, the diverticulum is accessed non-invasively and optionally cleaned to remove unwanted matter therefrom. The remodeling agent is introduced into the diverticular interior and the neck of diverticulum is closed (as necessary) to prevent egress of the remodeling agent. The remodeling agent can be any of a variety of materials, including small intestine submucosa (SIS) collagen or other absorbable fibrosis materials in gel, liquid or solid form. An endoscopic device may be used that includes a multi-lumen flexible catheter having a distal end adapted to be steered through a patient and a proximal end that remains outside the patient's body.