_Intestinal concretions (calculi or stones in the intestines)._--These concretions are usually found in the large bowels, though they are occasionally seen in the small intestines. They are of various sizes, weighing from 1 ounce to 25 pounds; they may be single or multiple, and differ in composition and appearance, some being soft (composed mostly of animal or vegetable matter), while others are porous, or honeycombed (consisting of animal and mineral matter), and others are entirely hard and stonelike. The hair balls, so common to the stomach and intestines of cattle, are very rare in horses. Intestinal calculi form around some foreign body, as a rule--a nail or piece of wood--whose shape they may assume to a certain extent. Layers are arranged concentrically around such nucleus until the sizes above spoken of are attained. These stones are also often found in millers' horses, as well also as in horses in limestone districts, where the water is hard. When the calculi attain a sufficient size and become lodged or blocked in some part of the intestines, they cause obstruction, inflammation of the bowels, colicky symptoms, and death. There are no certain signs or symptoms that reveal them. Recurring colics of the type of impaction colic, but more severe, may lead one to suspect the existence of this condition. Examination through the rectum may reveal the calculus. The symptoms will be those of obstruction of the bowels. Upon post-mortem examinations these stones will be discovered mostly in the large bowels; the intestines will be inflamed or gangrenous about the point of obstruction. Sometimes calculi have been expelled by the action of a physic, or they may be removed by the hand when found to occupy the rectum. As in concretions of the stomach, but little can be done in the way of treatment more than to overcome spasm (if any exists), and to give physics with the hope of dislodging the stone or stones and carrying them on and outward.