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.
1 These symptoms usually represent simple infections such as bronchitis or sinusitis. 2  They could be symptoms of cancer of the lung, head, and neck. 3  Anyone with a cough that lasts more than a month or with blood in the mucus that is coughed up should see a doctor.