This paper presents updated recommendations on clinical nutrition in gastrointestinal diseases, developed by the Clinical Nutrition and Metabolism Section of the Polish Society of Gastroenterology. The aim is to systematize and update knowledge on the diagnosis and management of malnutrition in various gastrointestinal conditions, including inflammatory bowel diseases, acute and chronic pancreatitis, liver diseases, and nutritional care in geriatrics. The primary goal of these recommendations is to provide practical, evidence-based guidance for clinical nutrition in gastroenterology. To achieve this, we reviewed, summarized, and integrated recent international guidelines, supplementing them with the latest available evidence where appropriate. A structured consensus process was conducted among experts, leading to the formulation of 67 key statements that reflect current best practices. The document provides detailed recommendations on indications and contraindications for enteral and parenteral nutrition, with a special focus on endoscopic accesses for enteral feeding. It also outlines practical principles regarding caloric requirements and nutritional strategies tailored to specific gastrointestinal disorders. These recommendations have been carefully developed with input from leading experts in gastroenterology and clinical nutrition, ensuring both scientific rigor and practical applicability for healthcare professionals. The following recommendations are highlighted as being particularly relevant in everyday clinical practice: Statement 16: We suggest starting nutrition supply through the established PEG and PEG-J within 3-4 hours post-surgery, and through D-PEJ within 24 hours post-surgery Statement 38: In severe exacerbation of ulcerative colitis, we suggest enteral nutrition as first-line management in patients with a functional gastrointestinal tract. We recommend parenteral nutrition in this patient group when the patient cannot be effectively fed by the gastrointestinal route. Statement 39: In malnourished patients with Crohn`s disease and indications for surgery, if possible, we recommend delaying surgery for 7 to 14 days or longer until nutritional status improves. The optimal timing of surgery should be based on the benefit of continued metabolic preparation and the urgency of surgery due to increasing or regressing clinical symptoms. Statement 41: We recommend early initiation of oral nutrition in patients with predicted mild acute pancreatitis after resolution of complaints, regardless of lipase activity. Statement 42: We recommend the inclusion of enteral nutrition from the start of hospitalization in all malnourished patients and patients with predictive factors for severe acute pancreatitis, and within 72 hours in all patients in whom oral nutrition does not cover 60% of protein-calorie requirements. Statement 53: In patients with liver cirrhosis, we recommend a daily total energy intake of 30-35 kcal/kg/d and a protein supply of 1.5 g/kg/d for malnourished patients and 1.2 g/kg/d for other patients, taking metabolic limits into account. Statement 54: We recommend withholding enteral feeding for 48-72 h after an episode of esophageal/gastric variceal bleeding (until bleeding is controlled), as enteral feeding makes endoscopic intervention more difficult, increases visceral flow, and may exacerbate variceal bleeding.