When lung cancer patients’ belly bulges in the late stage, the following three possibilities are mainly considered: 1. This can also lead to a bulging stomach; 3. Hypokalemia can cause intestinal paralysis, which can lead to a large amount of abdominal distension. Because patients with advanced lung cancer often have poor diet, they are prone to hypokalemia, which leads to intestinal paralysis and decreased intestinal peristaltic function, resulting in more gas in the intestine, which leads to abdominal distension, manifested as abdominal bulging.