In case of indigestion the vomitus is usually acid. It is alkaline in cases of catarrh and cholera.

Vomiting may be watery, alimentary, bilious, fecal. hemorrhagic, or purulent.

Aqueous vomiting is often viscid and soapy because of the presence of mucous. It is seen in alcoholic gastritis, ulcer, cancer, sick stomach, and cholera.

Alimentary vomiting is of food recently swallowed. Bilious vomiting shows the bile in the ejected matter.

Fecal vomiting is of the contents of the bowels, and means obstruction.

Blood vomiting may be hemorrhage of the stomach. If bright red, it means ulcer; when dark and like coffee grounds, it indicates cancer.

False membranes, and long casts of mucous, are sometimes passed. These indicate muco-entero-colitis.

White, jointed, tapelike appearances may be tapeworms. If found, watch should be kept for a few weeks. If there is really a tapeworm, portions of it will pass almost weekly.