Part C of this chapter synthesizes disorders of the small and large intestines. Covered entities span malabsorption and its etiologies, functional disorders and enteropathies, inflammatory bowel diseases, colorectal polyps and polyposis syndromes as well as the most relevant anorectal conditions. Epidemiology, risk factors, key diagnostic features, sentinel complications, and implications for management, intervention, and surveillance are described. For many of those medical impairments, considerations of significant malabsorption and malnutrition, colorectal cancer risk, risk of other gastrointestinal and extra-gastrointestinal cancers, risk by extra-intestinal organ manifestations, associated conditions and comorbidities, and functional impairments play a significant role in risk assessment. Besides information on mortality and morbidity, particular attention is paid to features that modify risk (especially cancer predisposition) so that prognosis can be stratified accordingly.