Hi my dear mother-to-be! The brown tissue plques you noticed in your stools. Have you noticed whether they have come from the anus or vagina. From the medical opinion you obtained, it appears that they had come from the vagina. Loosing the mucous plug means that the mucous which throughout the pregnancy is sitting in the mouth of the uterus (Cervis) is now getting dislodged. This happens when the cervix is preapring to open up for allowing the baby to come out during lebour. The cervix starts getting thinned out and starts opening. That is why the mucous plug is dislodged which comes out of vagina. This mucous plug is associated with some amount of blood giving it reddish to brownish colour. This is called as the show . I feel, your labour pains will start soon, may be within a weeks time or less. I hope I have answered your query to your fullest satisfaction. If there is any further question in your mind, I am available to you. Wish you a good health and happy and safe motherhood.