A fecal fistula is an abnormal passage between the genital organs and the intestine. So, what are the reasons for the appearance of transvaginal discharge during thin stool? Here is a brief introduction. Causes of transvaginal discharge when stool is diluted 1, birth injury: (1) compression necrosis (2) birth canal tear (3) obstetrical surgery injury. 2, local treatment injury: (1) uterine prolapse injection injury (2) uterine prolapse injection injury (3) injury caused by radiation therapy. 3, congenital malformation: clinically rare, mainly the ureteral orifice ectopic and congenital hypospadias, the former is one side of the ureteral opening in the vaginal side of the vault or vestibule and other parts of the child after birth, both leakage of feces, but also can solve part of the feces, the latter is the urethra opening in the vaginal orifice or vagina, the lighter more than obvious symptoms, the heavy urethra posterior wall is absent, the bladder directly open in the vagina, so that urination completely can not Some patients with hypospadias, where the urethral opening is in the lower 1/3 of the urethra, can control urination before delivery, but after delivery there is fecal leakage due to the relaxation of the pelvic floor muscles and the expansion of the anterior vaginal wall, which can be clinically misdiagnosed as fecal fistula due to birth injury. 4, disease injury: the more common urinary fistula caused by disease injury are the following: (1) bladder stones, due to stone compression of bladder tissue, resulting in tissue ischemia necrosis and fistula formation. (2) Urinary fistulas due to tuberculosis of the bladder are most often seen in young girls. The lesions often occur first around the ureteral orifice, gradually spreading to the bladder triangle and then to the entire bladder, where the bladder mucosa becomes edematous and congested, later forming tuberculous nodules, case-like changes and ulcers, and finally the lesions invade the muscular layer causing fistulas. (3) Advanced cancers of the genitourinary organs cause fistulae due to infiltration of cancerous tissue and destruction of the vaginal wall.