This book provides substantial update on the recent researches in colonic disorders. The 21st century has witnessed a revival of research of the gastronomical tract, particularly since it was discovered that it has a primary role as an immune system organ and subsequently, has a great effect on transmission, affect and causation of most human ailments. Diseases like AIDS, hepatitis and tumors of the gastrointestinal tract have surfaced and they are presently subjects of intensive research and topics of scientific papers published across the world and earlier diseases like diarrhea have become greatly complicated to diagnose with novel and old pathogens, tumors, drugs and malabsorptive disorders accounting for the confusion. This book presents algorithms on how to approach such conditions in an organized way both to reach a diagnosis and to make patient care more effective and cheaper. It aims to compile all the novel information into proper perspective with stress on aetiopathogenesis and present rational approach towards management of several old and new diseases.