Aim of the study: To evaluate the effect of the nursing instructions on reducing the selected functional gastrointestinal disorders among elderly patients. Research design: Quasi-experimental (Pre–posttest). A consecutive sample of one hundred elderly patients was included in this study. Setting: The current study was carried out at a Geriatric home, Geriatric club, and Gastrointestinal clinic at Qena two tools were utilized to collect data, First Tool: A Structured interviewing questionnaire sheet, personal data (age, gender, marital status level, etc.)Second Tool: The Patient Assessment of Constipation-Symptoms questionnaire. Results: there was a highly statistically significant difference in total mean average score and SD (20.4 ±8.3, 10.8 ±8.3) of constipation symptoms severity during pre and post-nursing instructions implementation p value≤0.05. Conclusion implementing the nursing instructions regarding selected functional gastrointestinal disorders among elderly patients reflected a significant impact on patient's outcomes of constipation this significant difference justified the research hypothesis. Recommendations: A continuous education and training are offered on regular basis for elderly patients regarding gastrointestinal disorders, in addition to educational classes for elderly people about age-related changes that affect their gastrointestinal tract and elimination pattern without a feeling of shame or embarrassment to prevent complications. Encouraging to improve the elderly home foods menu to contain high fiber foods such as vegetables and fruits to over com constipation problems