Old fart is not necessarily cancer. Anal exhaust, commonly known as fart, is mainly produced by the decomposition and metabolism of food in the intestine, and the odor of fart is mainly caused by the high content of ammonia and hydrogen sulfide. 1. Excessive consumption of high-protein food, such as fish, shrimp and seafood, will lead to food decomposition and produce a large amount of ammonia, hydrogen sulfide and other gases, causing the fart to present a special odor. 2. Some other patients with indigestion, due to The first thing is that the patient’s fart will not be able to be used as a fart. Therefore, patients with stinky fart are not necessarily caused by cancer, but more likely caused by other lesions in the intestinal tract, which need further examination to determine.