Before answering whether or not constipation causes fever, we must understand when and why an individual develops a fever.Fever is basically having a temperature above the normal range due to an increase in the body's temperature set-point. A fever can be caused by many medical conditions ranging from viral, bacterial and parasitic infections such as the common cold, urinary tract infections, meningitis, malaria and appendicitis among others. In these conditions your body can be compared to a state of war, where there are cells called inflammatory mediators that are fighting the infectious agent. These produce agents called pyrogens which in turn reset the temperature set point at an area of your brain called Hypothalamus. But then if constipation would cause a fever, how would it?
So basically Constipation refers to abnormally infrequent bowel motions and/or pain or difficulty when passing small, hard stools.At the Centre for Digestive Diseases long standing research in this area has indicated that the most likely cause of the common variety constipation found in the majority of patients is caused by an infection with a bacterial agent that has entered the bowel through the mouth and has begun to coexist with normal human bowel flora. Its presence in the bowel flora is marked by the production of molecules within the bowel which affect the enteric nervous system so partially paralysing the bowel. If the constipation agent produces severe paralysis the bowel may not empty for days or weeks.The actual causative agent or agents are yet to be detected. However it has been proposed that a bacteria called clostridium is implicated.
Now this bacteria works by producing a toxin which is a neurotoxin. Presence of this toxin alerts your body to produce inflammatory mediators which cause the fever as explained above.
Hence constipation is often said to be caused due to a chronic bacterial infection and this can be associated with fever, in simpler words constipation as such might not cause a fever per se but could be associated with it.
But this is not the only proposed theory regarding the same.Common complications of constipation include
→ Fecal impaction that is a solid, immobile bulk of human feces that can develop in the rectum due to altered bowel movements
→ Swollen veins in your anus (hemorrhoids),torn skin in your anus (anal fissure), intestines that protrude from the anus (rectal prolapse).
These conditions also rarely could lead to a fever,hence complications of constipation such as fecal impaction,anal fissures, rectal prolapse etc could be implicated in the causation of fever in this condition.
So if you are a victim of constipation and have developed a fever off late, there could be a relation between the two and it is advised you consult a physician.