Patients with chronic renal failure who experience vomiting generally indicates that their condition has become very severe. Typically, from stage four of chronic kidney disease onwards, a large amount of metabolic waste accumulates in the body, and patients may have severe metabolic acidosis, among other issues. These conditions can cause edema of the gastrointestinal mucosa, and these metabolic wastes can also irritate the gastrointestinal tract, leading to symptoms like nausea, vomiting, and loss of appetite. Of course, besides these reasons, other gastrointestinal diseases such as chronic gastritis, gastric ulcers, and even gastric cancer should also be ruled out.