Researchers at Yale, in a mouse study, discovered that herpes simplex 1 can cause nerve damage in the colon that prevents proper digestion.
Individuals with herpes have reported seemingly unrelated symptoms such as constipation and urinary retention (inability to empty the bladder), but the mechanism was not understood. The research team, led by Akiko Iwasaki, professor of immunobiology and Howard Hughes Medical Institute investigator, decided to investigate using mice models of herpes simplex virus-1, the dominant cause of genital herpes in the United States.
https://www.sciencedaily.com/releases/2016/06/160608142544.htmThey found that the herpes virus spread from the genitals to nerves in the spinal chord, and then on to neurons in the colon, killing them. The damage to the colonic neurons prevented the movement of food along the digestive tract, leading to an enlarged colon and disease.