Half yellow and half brown stools can have both physiological and pathological causes. Physiological causes are normal, including darker colored food and medications. Pathologic causes, such as gastrointestinal bleeding, are not normal. 1. Physiological reasons: if you eat too much animal blood, liver, spinach and other foods, the stool may appear half yellow and half brown; certain drugs such as iron (ferrous fumarate, ferrous sulfate, etc.), bismuth (colloidal bismuth pectin, bismuth citrate potassium, etc.), etc., a long time to take the color of the stool will lead to changes in the stool, resulting in half-yellow and half-brown stools. 2. Pathological causes: such as peptic ulcer, rupture of esophagogastric fundus varices, colitis, etc., resulting in gastrointestinal bleeding, which leads to brown stools. If you exclude the food and drug factors, it is recommended to consult a doctor in time to clarify the cause of the disease.