There are particularly many reasons for having liquid in the anus. First, if it is ulcerative proctitis, it generally invades the rectal mucosa and submucosa, producing mucus and also pus locally, and discharging a small amount of liquid from the anus during bowel movements. Secondly, if internal hemorrhoids are combined with bleeding, generally due to the contraction of the anal sphincter, a small amount of bleeding will enter the rectal pot belly against peristalsis, and a small amount of liquid can be discharged during defecation. Third, if rectal damage or foreign body invasion causes rupture of rectal mucosa or submucosal blood vessels, sometimes it will also lead to liquid in the anus, usually blood in the stool. Therefore, do not be nervous when there is liquid in the anus. You can perform rectal diagnosis or anoscopy for clear examination, and if necessary, use colonoscopy to observe the cause and location of the lesion.