Shiftingdullness is a common clinical method to check for fluid accumulation in the abdominal cavity. The principle is that when more fluid accumulates in the abdominal cavity (about 1000ml or more), when the patient is percussed in the supine position, the fluid accumulates in the low part of the abdominal cavity due to gravity, and the intestinal tube containing gas floats on it, so the percussion shows a drum sound in the middle of the abdomen and a turbid sound on both sides of the abdomen. Positive mobile turbid sounds indicate the presence of fluid in the abdomen. Then, the prevention of mobile turbid sounds is also the prevention of fluid in the abdominal cavity, there are probably a few points: 1, pay attention to diet, to prevent overeating. 2, more exercise to increase the body’s immunity and protect the function of internal organs. 3, surgery, health care workers strictly implement the principle of aseptic operation. 4, develop reasonable dietary habits: maintain a light diet, eat more fresh vegetables and aquatic products, such as green vegetables, radish, seaweed, nori, etc. Eat less and more meals, forbid fatty meat and animal offal, and do not eat irritating onion, pepper, coffee, etc.