This chapter discusses the polysaccharide-based nanoparticulate formulations targeted for colonic delivery, which helps to understand the developments and technologies being utilized to target the colon for drug delivery in a much better and efficient manner. Nanoparticulate formulations would help to solve the limitations of colon-targeted drug delivery systems due to the several advantages of nanosize formulations which can penetrate the mucous layer and epithelial membrane effectively due to their smaller size and ensure better tissue penetration of the affected areas of the colon. The chapter also discusses the physiology of the large intestine and colon highlighting its gross anatomy, microscopic anatomy, blood supply, and functions. Polysaccharides obtained from nature are one of the major sources extensively used for solid oral dosage forms of colonic drug delivery. Polysaccharide-based nanoparticles have immense possibilities for future research and development and for providing the best possible management of the colonic diseases whose treatment remains questionable.