The normal form of feces is formed soft stool, yellowish brown, with a small amount of mucus, and the abnormality can be manifested as dilute watery stool, mucus stool and deformed stool. 1. Thin watery stool: it can be manifested as wash water or rice slop, which can be seen in maldigestion and malabsorption, Vibrio parahaemolyticus food poisoning, AIDS complicated with cryptosporidiosis, cholera and so on. 2. Mucus stool: It is manifested as mucus mixed in feces or mucus adhering to feces surface. When accompanied by intestinal mucosal necrosis, it can be manifested as mucus, pus and blood stools, which can be seen in intestinal inflammation, tumor, some bacterial dysentery. 3. Metamorphic stool: it can be seen as spherical hard stool, thin strip, flat shape, which can be seen in habitual constipation, rectal or anal stenosis, colorectal cancer, and so on. When the feces is not yellow soft stools should be timely medical care, clear cause, under the guidance of professional doctors to choose the appropriate treatment.