Problems of constipation, diarrhoea and irritable bowel syndrome are common. Infective diarrhoeal diseases are a significant cause of morbidity and mortality worldwide, especially in infants and management of these conditions is reviewed. • Constipation: mode of action and use of drugs • Diarrhoea (drug treatment importance of fluid and electrolyte replacement) • Inflammatory bowel disease • Irritable bowel syndrome STOOL BULKING AGENTS Dietary fibre comprises the cell walls and supporting structures of vegetables and fruits. Most of the fibre in our diet is in the form of nonstarch polysaccharides (NSP),1 which are not digestible by human enzymes. Fibre. | 32 SECTION 7 Intestines SYNOPSIS Problems of constipation diarrhoea and irritable bowel syndrome are common. Infective diarrhoeal diseases are a significant cause of morbidity and mortality worldwide especially in infants and management of these conditions is reviewed. Constipation mode of action and use of drugs Diarrhoea drug treatment importance of fluid and electrolyte replacement Inflammatory bowel disease Irritable bowel syndrome The terms purgative cathartic laxative aperient and evacuant are synonymous. They are medicines that promote defaecation largely by reducing the viscosity of the contents of the lower colon and are classified as follows Stool bulking agents Osmotic laxatives Faecal softeners Stimulant laxatives. STOOL BULKING AGENTS Dietary fibre comprises the cell walls and supporting structures of vegetables and fruits. Most of the fibre in our diet is in the form of nonstarch polysaccharides NSP 1 which are not digestible by human enzymes. Fibre may be soluble pectins guar ispaghula or insoluble cellulose hemicelluloses lignin . Insoluble fibre has less effect than soluble fibre on the viscosity of gut contents but is a stronger laxative because it resists digestion in the small bowel and so enters the colon intact. In addition it has a vast capacity for retaining water thus one gram of carrot fibre can hold 23 grams of It has been proposed that as humans have refined the carbohydrates in their diet over the centuries so they have deprived themselves of fibre the ensuing under-filling of the colon being an important cause of constipation haemorrhoids and diverticular disease. Stool bulking agents which add fibre to the diet are the treatment of choice for simple constipation. They act by increasing the volume and lowering the viscosity of intestinal contents to produce a soft bulky stool which encourages normal reflex bowel activity. The mode of action of stool bulking agents is thus more physiological than other types of .
