DEF meaning in Medical ?

Defecation (or defaecation) is the final act of digestion, by which organisms eliminate a solid, semisolid, or liquid waste material known as feces from the digestive tract via the anus. The act is known by a variety of terms ranging from the common, like pooping, to the technical, i.e. bowel movement. There are too many colloquial terms to mention. The topic, usually avoided among polite company, can become the basis for some potty humour.

Humans expel feces with a frequency varying from a few times daily to a few times weekly. Waves of muscular contraction (known as peristalsis) in the walls of the colon move fecal matter through the digestive tract towards the rectum. Undigested food may also be expelled this way, in a process called egestion. When birds defecate, they also expel urine and urates in the same mass, whereas other animals may also urinate at the same time, but spatially separated. Defecation may also accompany childbirth and death. Babies defecate a unique substance called meconium prior to eating external foods.

There are a number of medical conditions associated with defecation, such as diarrhea and constipation, some of which can be serious. The feces expelled can carry diseases, most often through the contamination of food. E. coli is a particular concern.

Before potty training, human feces are most often collected into a diaper. Thereafter, in many societies people commonly defecate into a toilet. However, open defecation, the practice of defecating outside without using a toilet of any kind, is still widespread in some developing countries. Some people poop into the ocean. First world countries use sewage treatment plants and/or on-site treatment.