Feces are dirty and smelly, and most people will not bother to look at them after a bowel movement. But experts say that taking a look after a bowel movement may reveal certain diseases hidden in the body. This is because changes in the color and nature of the stool are often one of the most important symptoms of digestive and rectal diseases. Changes in color: Darkened stools, called tarry stools, are often a sign of upper gastrointestinal bleeding. Blood is originally red, and when it enters the digestive tract, the iron from the hemoglobin in the blood combines with the sulfides in the intestines to become iron sulfide, giving the stool a tarry black color. Consumption of certain foods or medications can also sometimes turn the stool black, such as bloody tofu, which should be distinguished. Stool with pus and blood may be colitis, dysentery or colon cancer. Stool with blood color bright red: after the stool drops or attached to the formation of the surface of the stool, or after the stool hand paper stained with blood, and stool is not mixed, commonly found in internal hemorrhoids, anal fissure, rectal polyps and so on. Jam-like stool, may be amoebic dysentery. Terra cotta color is seen in case of complete obstruction of the biliary tract or after taking barium meal contrast. Changes in shape: Stools that are thin, or irregular or have an indentation should be carefully examined in the hospital, except for polyps or tumors. Dry stools or fecal pellets are signs of constipation. Changes in the nature of the stool: such as the stool from dry to thin, from thin to dry, thick to thin, or changes in the number of times of toileting, should be noted, and go to the hospital for examination in a timely manner. Especially remind the elderly, because the age itself has decided that the elderly is the vulnerable group of tumor and the main cause of death. Therefore, they should be especially alert to the occurrence of colon cancer and rectal cancer, and the change of bowel movement is often an important manifestation of these two diseases, so they must pay attention to the observation so as not to miss the best time to seek medical treatment. Generally speaking, 3 times a day to 1 time in 3 days is a normal phenomenon, and the feces are mostly soft stools in the form of strips, with the color of brown or yellow. For how to keep the bowel movement, experts suggest that: to ensure that the mood is comfortable, bad mood on the gastrointestinal tract will have an impact; reasonable diet, eat more fruits, vegetables, etc., avoid spicy, fried food; strengthen physical exercise, promote gastrointestinal peristalsis; to develop good habits of defecation, don’t read in the toilet reading the newspaper. Regular defecation. Another very important point is that laxatives should not be abused.