If the stool is black like snowflakes, no special treatment is needed if it is caused by improper diet. If it occurs repeatedly, it is considered to be a condition such as gastrointestinal bleeding and needs to be treated. Foods such as nori, pig liver, and pig blood can cause black stools, and an unclean diet can also cause diarrhea and unformed stools. When black stools like snowflakes occur occasionally after eating such foods, there is no need to be overly nervous. However, if patients repeatedly experience abdominal pain, diarrhea and unformed stools, and do not get relief even after adjusting the type of food and controlling food hygiene, they need to consider the possible existence of gastrointestinal bleeding and should promptly go to the gastroenterology department for gastroscopy and colonoscopy to clarify the cause and then carry out relevant treatment. Patients should usually pay attention to dietary hygiene, eat less spicy as well as raw, cold and hard foods, and if the symptoms continue to worsen, they should be treated actively.