Routine stool examination includes the observation of the appearance of stool such as color, properties, odor and microscopic examination. Normal stool is generally free of red blood cells and white blood cells when observed under the microscope, and can be considered normal if white blood cells are occasionally seen. If there is an increase in leukocytes in stool, it is common in enteritis and bacterial dysentery; while an increase in red blood cells above the normal range is common in lower gastrointestinal bleeding, intestinal inflammation, colon cancer, rectal cancer, rectal polyps, bleeding hemorrhoids, etc. If parasitic eggs, worms or protozoa are found, the corresponding parasitic or protozoal infection can be identified.