In the algid type of pernicious malaria the abdominal griping may be severe.
Tenesmus is the condition which along with tormina gives a diagnosis of some form of dysentery.
In rectal schistosomiasis the thickenings and blood extravasations, resulting from the eggs extruded by the fluke, may give rise to prolapse of the rectum. This may also occur in severe bacillary dysentery and in a disease of British Guiana and Venezuela, known as epidemic gangrenous rectitis, prolapse and gangrene of the rectum may occur. The symptoms are those of gangrenous dysentery.
Diarrhoea
The chronic diarrhoeas of the tropics are often associated with amoebic dysentery and in such cases we generally get a history of recurring attacks of diarrhoea separated by periods of constipation.
In sprue the condition generally sets in as a morning diarrhoea, very profuse and painless. Hill diarrhoea also shows frequent stools of whitish color from early morning until about noon.
The typical stool of sprue is a gas-permeated, putty-colored, offensive mass, extraordinarily copious.
In cholera the rice-water stool, which is not attended by pain, causes an unusual sense of prostration even at the onset of the stage of evacuation.
In pellagra we often have a recurring diarrhoea or mild manifestations of dysentery.
The stool of pellagra is darker and less copious than that of sprue and shows only a normal fat content while that of sprue is very fatty—as much as 30% of ingested fat appearing in the sprue stool as against the 5% for the normal one.