Health Conditions that Cause Mucus in Stool. A sudden onset of mucus in the stool, accompanied by urgent diarrhea, cramping, fever, and blood in the stool may be indicative of a bacterial infection. If you are having any of these symptoms, contact your physician immediately.
Atelectasis, or localized obstruction of the lungs that may result from mucus plug obstruction, can occur resulting to the collapse of a portion of the lungs. This is enumerated by the study published by Respiratory Care in September 2007.
Mucus plug: An accumulation of mucus and thick fluid that blocks the opening of the cervix (the opening from the uterus to the vagina) during pregnancy. The mucus plug serves to protect the uterus and the fetus by preventing bacteria from entering the uterus. The mucus plus can be clear or slightly pink in color and can be tinged with brown or red blood. As the cervix slowly begins to dilate prior to the onset of labor, the mucus plug is expelled.