This paper presents different nutritional and biological activities of resistant starch in human organism. Resistant starch fractions may indicate some physiological functions remaining in relation with their physical and physico-chemical properties, including water holding capacity, intestinal transit time, potential glycaemic index, insulin action, induction of thermogenesis (gases, ammonia, phenols), mineral absorption, intestinal pH. Colonic function, especially bowel habit, short-chain fatty acids production, N-metabolism, bacterial activity and epithelial cell function are largely controlled by carbohydrates that enter the colon as well as, the resistant starch (RS), non-starch polysaccharides (NSP) and oligosaccharides. The relationship between diet, microflora and colorectal cancer is complex and intimate. Substances entering the colon from ileum and the resident microflora are major determinants of colonic physiology. These, together with the innate biology of the colon, are pertinent to the initiation and promotion of colorectal cancer. The biological activity of resistant starch, as it results from the recent literature data, can also positively influence the prevention of gastrointestinal disease.