Catarrhal diarrhoea

Catarrhal diarrhoea is the ordinary form of non-infectious diarrhoea. It occurs when the intestinal mucous membrane is in much the same condition of congestion and swelling as the nasal membrane during a "cold of the head", and secretes a great amount of clear, viscid mucus of a similar nature to that coming from a runny nose.

Uncomplicated catarrhal diarrhoea may be produced in a slight degree by indigestible food, by nervous excitement, or as the result of a chill or change of weather. In severer form it may be due to Salmonella bacteria, which are responsible for food poisoning, or to drugs. It may precede many diseases, such as appendicitis or a urinary tract infection.