Diseases of the gastrointestinal system

This chapter deals with common diseases and disorders that affect the gastrointestinal system. The chapter begins with symptom based, common gastrointestinal complaints and briefly describes the system specific clinical examination methods and investigations employed in the diagnosis of disorders of the gastrointestinal system. Since the oral cavity is a part of the gastrointestinal system, common mucosal diseases such as stomatitis, oral ulcers and gingival enlargements are discussed. Disorders of the oesophagus and intestines discussed in this chapter include dyspepsia, dysphagia, gastro-oesophageal reflux disease, gastritis, hiatus hernia, gastroenteritis, appendicitis, acute abdomen, peptic ulcer disease, gastric and duodenal ulcer, celiac disease, inflammatory bowel disease (IBD), Crohn's disease and ulcerative colitis, irritable bowel syndrome (IBS), haemorrhoids, dysentery (amoebic and bacillary dysentery), malabsorption and diarrhoeal disease. Each disease entity starts with a definition or description followed by its causes, symptoms, signs, the investigations employed and the principles of management. Oral and dental aspects of the gastrointestinal diseases are also described in this chapter.