In one aspect, the invention provides injectable compositions that comprise a suitable hydrophilic polymer (e.g., a suitable polysaccharide) and water, as well as other optional components. In various embodiments, the composition may be provided in a suitable container, for example, in a pre-loaded syringe. In another aspect, methods of performing medical procedures in a tract of a body are provided. In yet another aspect, the invention provides systems for performing medical procedures in a tract of a body.