Recently, some patients felt bloated and uncomfortable and thought they had digestive disorders, but gastroscopy did not show any significant abnormalities, and they were treated with conventional medications to protect the gastrointestinal mucosa without any significant improvement. When thyroid hormone is increased in human body, it can promote faster gastrointestinal emptying, shorter conversion time of small intestine and increased peristalsis, so it can be seen that the appetite is strong, the amount of food is obviously more than normal, but still feel hungry, indigestion, increased frequency of stool and paste-like. Due to the direct toxic effect of thyroid hormone on the liver, hepatocytes become degenerative and necrotic due to relative hypoxia, thus liver and liver function damage, increased transaminases and even jaundice can be seen. When the thyroid hormone is insufficient and the thyroid gland is hypothyroid, the patient does not show hyperphagia, but decreases appetite, and bloating and constipation are common due to the weakened bowel movement. Thyroid hormones have a metabolic stimulating effect and can affect gastrointestinal motility. Patients with hyperthyroidism often experience hyperphagia, increased frequency of stools or diarrhea due to enhanced gastrointestinal motility, faster emptying of the gastrointestinal tract, and shorter transformation time of food in the small intestine. In addition, too much thyroid hormone can increase oxygen consumption in the liver, liver glycogen deficiency, hepatocyte hypoxia and degeneration necrosis, liver function, manifested as liver, jaundice, and even cirrhosis. Hypothyroid patients have slowed gastrointestinal motility, slowed gastrointestinal emptying, and often have decreased appetite, constipation and flatulence. So when there are patients with digestive symptoms that do not improve after treatment, they should consider whether it is due to thyroid-related diseases and further check if there is a problem with thyroid hormone secretion.