After foods are eaten and broken down into usable elements, nutrients are absorbed and indigestible materials are eliminated. Bowel elimination is the end process in digestion. This chapter describes the structure and function of the large intestine, including the rectosigmoid region and the anus, as well as the assessment of bowel function. The anatomy and physiology of the small intestine are discussed in relation to nutrition in Chapter 21; the information in this chapter is provided as a base for understanding health problems from altered bowel function. In addition, this chapter discusses the function of the small intestine in the absorption of digested end products. Malabsorption (impaired absorption of nutrients) is discussed fully in Chapter 26.