This invention relates to the treatment and diagnosis of abnormalities of the epithelial-lined surface of the esophagus and, in particular, to esophageal stents having a surface coating comprising a photosensitizing agent or a precursor thereof for use in methods of photodynamic treatment (PDT) or photodynamic diagnosis (PDD) of the esophagus. The stents find particular use in methods of diagnosing and/or treating Barretts esophagus and in diagnostic methods for monitoring the progression of the disease.
