Objective:To study the correlation between nutritional status and length of hospital stay in patients with digestive disorders.Methods:The data were collected from the database of a multi-center investigation on the dynamic changes of nutritional status of hospitalized patients in China, a project led by the Geriatric Nutrition Support Group, Society of Parenteral and Enteral Nutrition, Chinese Medical Association. The enrolled patients were screened for malnutrition and possible sarcopenia using Global Leadership Initiative on Malnutrition criteria, and the dynamic changes of serum biochemical indexes during hospital stay and the effects of malnutrition and possible sarcopenia on the length and cost of hospital stay were analyzed.Results:A total of 1 180 patients were enrolled, with an average age of (56.3±16.1) years, the average height of (164.65±8.29) cm, and the average weight of (62.12±12.12) kg. There were significant differences in body weight, body mass index, calf circumference, lymphocyte count, triglyceride, hemoglobin, albumin and total protein between at discharge and at admission ( P<0.001). There might be a correlation between post-admission malnutrition and sarcopenia. There was neither significant difference in the proportion of patients with malnutrition at admission among different age groups ( P=0.438), nor in that at discharge among different age groups ( P=0.439). The proportion of patients with malnutrition showed no significant difference between subgroups with patients<65 years old and ≥ 65 years old, at admission and discharge ( P>0.05). However, comparison of the proportion of patients with sarcopenia between subgroups with patients<65 years old and ≥65 years old displayed significant differences at admission and discharge ( P<0.001), but not the comparison of the proportion of patients with possible sarcopenia ( P>0.05). The length of hospital stay in patients with malnutrition was significantly longer than that in patients without malnutrition [(13.22±6.24) days vs. (12.08±5.25) days, P<0.001]. The length of hospital stay of patients with and without sarcopenia was also significantly different [(12.87±5.93) days vs. (12.02±5.22) days, P<0.001). Patients with concurrent malnutrition and sarcopenia had longer hospital stay [(14.57±7.15) days vs. (12.07±5.22) days, P<0.001], and higher medical cost [(2.78±2.19) ten thousand Chinese Yuan vs. (2.24±2.33) ten thousand Chinese Yuan, P<0.05)] compared with those without concurrent malnutrition and sarcopenia. Conclusions:A large proportion of patients with digestive disorders were diagnosed with malnutrition and/or possible sarcopenia during hospitalization. There is possible correlation between malnutrition and possible sarcopenia, and both can lead to a longer hospital stay and higher medical cost.