Below are the main rubriks (i.e strongest indications or symptoms) of Merc Viv in traditional homeopathic usage, not reviewed by the FDA.
RECTUM, ANUS, STOOL
Stools undigested, pitch-like, tenacious; yellow, dark-green, mucous and bloody; sour, excoriating the anus; clay-colored and offensive; slimy, bloody, preceded by anxiety, trembling, faintness; colic; tenesmus; after stool, tenesmus a "cannot get done" feeling, followed by chilliness.
Blood before, during and after, even a hard, stool.
Constipation, stool tenacious or crumbling discharged only with violent straining; constant, ineffectual urging, worse at night.
Ascarides and lumbrici escape freely.
Prolapsus ani after stool; also, if rectum is black and bleeding.
Large bleeding varices, which suppurate; hemorrhage after micturition.≡ more ...