Patients with smelly and sour stool, consider two reasons, as follows: 1, improper diet: a large number of high-protein, high-fat diet, because high-protein food in the intestinal tract, fermentation, a very strong odor. 2, disease factors: be careful to rule out the presence of chronic pancreatitis, when the pancreas loses more than 90% of its exocrine function, there will be pancreatic exocrine insufficiency, resulting in eating pancreatic secretion is difficult to maintain a normal Food digestion, manifested as emaciation, bloating after meals, loss of appetite, indigestion and malabsorption, and even steatorrhea, stool discharge, stool will have a foul, sour smell, foamy, floating on the surface of the water, microscopic examination can be seen in the lipid droplets and muscle fibers, and if left untreated, it will lead to a decrease in the level of fat-soluble vitamins in the circulation. When there is a change in stool traits, odor, and color, it is important to go to the hospital for relevant examinations and give comprehensive treatment to avoid delaying the condition.