Two colors of stool may be caused by constipation, irregular diet, digestive tract tumors and other reasons. 1. Constipation: If there are two colors of stool, it may be caused by constipation. When the feces accumulate in the anus and lower part of the intestine for too long, they will be oxidized, which will make the feces darker and the later feces lighter, and the general color is shown as dark in the front and light in the back. 2. Irregular diet: when patients have irregular diet for a long time, the digestion and absorption ability of intestines decreases, and undigested food will be discharged with stool, which may lead to two colors of stool. 3. Tumor in digestive tract: If the patient suffers from tumor in digestive tract, the brittleness of blood vessels around the tumor increases, which may lead to bleeding during defecation, and the blood will be discharged with the stool, thus the stool appears in two colors. There are many other reasons for two colors of stool, so we suggest that patients should consult the doctor in time, complete the relevant examination, clarify the cause of the disease, and standardize the treatment under the doctor’s guidance.