A fecal fistula is an abnormal passage between the genital organs and the intestine. So, what is the differential diagnosis of fecal fistula with vaginal discharge? Here is a brief introduction. 1, external anal sphincter rupture: the external anal sphincter starts from the dorsal side of the tip of the tailbone and the anal caudal ligament, forward and downward, divided into two parts at the back of the anus, around both sides of the anal canal to the front of the anus, and then merge into one to stop at the perineum. The external sphincter is a random muscle divided into three parts: subcutaneous, superficial and deep by the interposition of the united longitudinal fibers. The subcutaneous part is generally recognizable, but the superficial and deep parts are not easily distinguishable, but the former is oval and the latter is round, and there is still a difference in appearance between the two. The external anal sphincter is innervated by the anal nerve and plays an important role in sphinctering the anus and controlling defecation, which can lead to fecal incontinence if inadvertently damaged during surgery. The fracture of the external anal sphincter can destroy the function of the external anal sphincter and lead to fecal incontinence. 2, anal fissure: anal fissure is a small ulcer formed after the skin layer of the anal canal below the dentate line is cracked and its direction is parallel to the longitudinal axis of the anal canal, about 0.5 to 1.0 cm long, pike or oval often causes severe pain and healing difficulties. In contrast, surface fissures of the anal canal cannot be considered as anal fissures because they heal quickly on their own and are often asymptomatic. Anal fissure is a common anal canal disorder and a common cause of severe pain at the anal canal in young and middle-aged people. Anal fissures are most common in middle-aged people, but can also occur in the elderly and in children, generally slightly more in men than in women, although more women than men have been reported. Anal fissures often occur in the posterior and anterior middle of the anus, with the posterior part of the anus being the most common and the sides less common. The fissure is linear or prismatic, and if the anus is opened, the fissure becomes round or oval in shape. 3.Drainage bloody stool: It refers to diarrhea and bloody stool caused by certain infectious factors that lead to impaired gastrointestinal function and damage to the gastrointestinal mucosa or due to other reasons, thus affecting the normal function of the body.