What is left of food after it has passed through the alimentary canal and subjected to the action of the digestive juices and after the nutritious parts have been absorbed by the intestinal mucous membrane. Also called ‘stools’ they contain various other matters, such as pigment derived from the BILE, and bacteria. Most adults pass faeces once daily, but infants have several evacuations of the bowels in 24 hours and some adults may defecate only two or three times weekly. Sudden changes in bowel habit, persistent diarrhoea or a change from the normal dark brown (caused by the bile pigment, stercobilin) to very pale or very dark stools are all reasons for seeking medical advice. Blood in the stools, while most commonly due to HAEMORRHOIDS, may be a sign of a more serious illness so needs investigation
of the bowels, or inability to retain the stools, is found in certain diseases in which the sphincter muscles – those muscles that naturally keep the bowel closed – relax. It is also a symptom of disease in, or injury to, the SPINAL CORD. Paradoxically it may also be a result of CONSTIPATION, particularly in children where it represents overflow of unformed faecal matter from above a partial obstruction by a mass of solid faeces – IMPACTION.
on defaecation is a characteristic symptom of a FISSURE at the ANUS or of inflamed HAEMORRHOIDS, and is usually sharp. Pain of a duller character associated with the movements of the bowels may be caused by inflammation in the other pelvic organs.
CONSTIPATION and DIARRHOEA are considered under separate headings.