Patients with kidney disease, especially those with renal failure, often have symptoms such as anorexia, nausea, vomiting and abdominal pain, diarrhea, and even gastrointestinal bleeding. The appearance of these symptoms is mostly related to protein loss, metabolic acidosis and renal failure. In renal disease, due to the large amount of protein loss and the formation of hypoproteinemia, not only the limbs appear edematous, but also the gastrointestinal tract is edematous, thus causing the dysfunction of the digestive tract, which manifests as nausea and vomiting. In renal failure, the excretory function of the kidneys is significantly reduced, and the body produces urea nitrogen and toxic substances such as guanidine, phenols, indoles, creatinine and uric acid, etc. As the concentration of these toxic substances increases or accumulates in the blood, it causes irritation of the gastrointestinal tract such as vomiting. In uremia, due to the change of human substance metabolism, the bacteria in the gastrointestinal tract can produce a substance called urease, and this enzyme can make the synthetic urine decompose ammonia again, and ammonia has strong irritation to the gastrointestinal tract, and can even form “uremic ulcers”, causing nausea, vomiting, loss of appetite, bleeding ulcers, etc.