Objective: The aim of the study was to establish the association of Phase angle at different time intervals as a risk factor for the development of complications, increase the number of hospitalization, reoperation and death and associate it with the stage of disease, PHD and diagnosis. Phase angle was observed as a predictor of malnutrition and its correlation with parameters obtained by biometric analysis of body composition was investigated. Materials and Methods: Data for the number and characteristics of patients were used for the TANITA version 3.2.5 scales for 2017, the NRS 2002 nutritional probe and the medical documentation of patients in colorectal surgery: the history of the disease and the PHD, for a total of 199 patients. Results: A statistically significant decrease in the value of Phase angle before surgery and in the period between the 1st and 2nd weeks after the operation was established in the direction that the Phase angle before surgery was statistically significantly higher than the Phase angle in the period of 1. -2. week after surgery. There is evidence of a negative correlation between age and value of Phase angle. A statistically significant correlation with Phase angle existed for the preoperative value of Phase angle for the period between 1-2 months and one month after the operation, while there was no statistically significant difference between the day of surgery and the 3-4 week period correlation between Phase angle and age. Furthermore, there is also a statistically significant difference in the Phase angle between the sexes. Women average have lower Phase angle values, and for the period statistically significant differences are seen for the preoperative value of Phase angle for the period between 1-2 months and one month after surgery until the day of surgery for a period of between 3 There is no statistically significant difference between Phase-Angle and Gender. Because of the oversized diagnosis and PHD, it is not possible to make a valid statistical treatment that would link the Phase angle value to the time with a specific diagnosis and PHD and no statistically significant correlation was found between the Phase angle value and the disease stages determined by the modified Dukes classification. Phase angle did not prove to be statistically significant for the development of complications as a cause of rehospitalization or reoperation. It did not affect the number of reoperations, hospitalization or length of hospitalization. Phase angle values prior to surgery and in the period between first and second weeks after surgery do not show statistically significant association with BMI. It has been shown that with Phase angle there is a positive correlation with muscle mass, TBW, bone mass and metabolic age in both observed periods, and that with Phase angle there is a negative correlation with ECW / TBW, negative correlation with the amount of fatty tissue , but only for preoperative values, and there is no correlation of the Phase angle with visceral fat values. It has been established that there is a negative correlation with Phase angle with preoperative NRS and that there is a positive correlation with albumin values on the day of surgery. There was also a statistically significant drop in albumin relative to the first performed operation compared to albumin after re-operation. Conclusion: Phase angle has not shown a good predictor of risk, but due to its good correlation with already known maladaptive predictors, the Phase angle has the potential to be included in this group. Given the strong correlation of the Phase angle with almost all body components, space is left to explore the movements of individual body components in the time that their changes affect the change of Phase angle.