De dysenteria theses

Physicians enumerate four species of bloody excretion through the stool, beyond that which occurs via hemorrhoids or wounds of the intestines, which they commonly include under the name of dysentery as a genus. Three of these are improperly named so, but one is named properly.

II.

The first of those improperly named is when blood, burdening nature with an excess of its own quantity, is propelled by the expulsive faculty—irritated—through the mesenteric veins, and is thence excreted through the stool. Such is the case when it sometimes happens after the amputation of a leg or arm, or when some customary evacuation, such as the menses or hemorrhoids, is suppressed.

III.

The second is similar to this, whence it is also included by some under the former. But it differs in this: that the cause of the former is an abundance of blood; but the cause of this is the acrimony of the same blood due to the admixture of bile, by which the orifices of the veins ending in the intestines are affected.

IIII.

The third follows a weakness of the retentive and alterative faculty in the liver and mesenteric veins.