During embryo formation, gastrointestinal epithelium and skin come from the same source. Therefore, the gastrointestinal tract is the most common site of visceral involvement in scleroderma, and patients with diffuse or localized diseases will have gastrointestinal symptoms to varying degrees. Due to the fibrosis of skin and subcutaneous tissue, it is difficult for patients to open their mouths, and the oral mucosa is dry, which is prone to periodontitis and gingival atrophy, leading to difficulty in eating, tooth loss and malnutrition. About 60% patients have fibrosis and muscle atrophy in the lower esophagus, the sphincter of the lower esophagus is weak, the tension decreases, and the wall of the upper esophagus expands and loses mobility. Patients often feel suffocated when swallowing, as if the food is blocked by something behind the sternum or in the heart socket of the upper abdomen, and the symptoms are more serious when lying down.

In severe cases, dysphagia may occur due to esophageal stenosis. The stomach is rarely involved, but the duodenum and jejunum are easy to be involved, and the intestinal peristalsis is reduced, so there may be no symptoms, or there may be mild intestinal dilatation and spasmodic abdominal pain, which is manifested by stomach cramps, and it feels more comfortable to press. Pseudointestinal obstruction can also cause severe intestinal dilatation, abdominal pain and vomiting. Pathological intestinal dilatation can not peristalsis, intestinal fluid accumulation is stagnant, and bacteria multiply in large numbers, which can cause malabsorption, and patients have symptoms such as diarrhea, malnutrition and weight loss. When colon and rectum are involved, patients often show scleroderma constipation scleroderma constipation scleroderma constipation scleroderma constipation scleroderma constipation scleroderma constipation scleroderma constipation constipation scleroderma constipation. For a long time after illness, patients with localized diseases will not have other important organs such as heart and kidney involved, or have mild symptoms and slow development. 1 ~ 3 years later, patients with diffuse skin and gastrointestinal symptoms are often prone to visceral involvement.