Thyroid problems
Even though the thyroid gland is located in the neck, it can cause problems lower down in the body. “The thyroid regulates several functions in the body and the digestive tract is one of the systems,” explains Dr. Alaradi. If the thyroid produces too much hormone (hyperthyroidism), it speeds up the digestive tract, resulting in diarrhea and abdominal cramps, he says. On the other hand, an underactive thyroid (hypothyroidism) slows down the digestive tract, potentially leading to pain from constipation and gas.