People experiencing constipation for no reason might unknowingly have Herpes, according to new research.

The new study has found a surprising link between gastrointestinal problems or the inability to empty the bladder and the the virus that causes genital herpes.

The Yale-led study showed that the virus is able to spread from the genitals to nerves in the spinal chord. From there, it travels to neurons in the colon – killing them off, and leading to damage.

Those problems can stop food from moving along the digestive tract properly, which can in turn lead to an enlarged colon and disease.

The findings could prove important for people who are suffering with gut problems and can’t find a cause, encouraging doctors to look at viral infection as a possible reason.

The study was led by Akiko Iwasaki, a professor of immunobiology at Yale. It is published this week in the journal Cell Host & Microbe.

“The key findings is that there is this unexpected infection in the neurons in the colon wall after herpes infection,” said Iwasaki. “Other members of the herpes virus family, including Epstein-Barr virus, chicken pox virus, and cytomegalovirus have been found in the neurons of the colon of people with unexplained chronic constipation. When doctors can’t figure out the cause of these chronic intestinal conditions, one thing to look at is a viral infection.”

The study tested the effects of the virus that causes herpes in mice. Though the effects in mice are different from those in people, the study is a way understanding how the disease processes through the body.