This section is from the book "Diseases Of The Intestines", by Max Einhorn. Also available from Amazon: Diseases Of The Intestines A Text-Book For Practitioners And Students Of Medicine.
Pancreatic calculi usually have a rough surface, are brittle, and may be faceted. They are soluble in chloroform and produce on evaporation an aromatic odor (Minich1). Bile pigment and cholesterin are absent.
Enteroliths or calculi formed in the small intestine usually consist principally of inorganic salts (lime, magnesia). They are light in color and ordinarily of small size. They occasionally form after an extensive use of mineral medicaments (lime, magnesia, etc.). They hardly ever give rise to intestinal obstruction.
Coproliths or fecal calculi are found in the large bowel, principally in places in which there is a retardation in the passage of the faeces. Thus they are encountered in the caecum, in the appendix, in sacculations of the colon, and in the rectum. The coproliths are of stony hardness and of sausage shape. They usually show on section concentric rings. Occasionally they attain considerable size and may give rise to obstruction of the bowel.
Foreign bodies which have been swallowed may pass through the entire intestinal tract and be eliminated in the faeces. Thus pieces of bone, coins, marbles, needles, and all kinds of foreign substances may be found in the stools. In rare instances concretions of shellac are discovered in the stools of patients who have drunk furniture polish, the shellac forming concretions after the absorption of the alcohol. Hair balls may be found in patients who habitually bite off and swallow hair.
1 Minich: Berliner klin. Wochenschrift, 1894, No. 8.