The patient’s anus appears liquid and has a fishy odor, mainly due to the following reasons: 1. It may be the cause of anal fistula, which occurs when there is recurrent flow of pus around the anus, as well as mucus discharge or even the occurrence of fecal water. When this happens the fishy smell is particularly obvious and itching around the anus occurs. The actual fact is that you can find a lot of people who are not able to get a good deal on this kind of things. 2, it is also possible that the patient has eczema in the anal area, and most of the causes of this disease are external factors. Therefore it can be treated with ointments that remove moisture and cure itching. These are the reasons for the fishy smell of liquid in the anus, in addition to if the patient has an anal fissure, it will also lead to a liquid and fishy smell.