An important complication of allo-SCT is GVHD, which commonly affects the skin, liver and digestive tract. Clinical symptoms of GVHD of the digestive tract (GVHD-DT) include excessive diarrhoea, abdominal pain and cramps, nausea and vomiting, gastrointestinal bleeding, dysphagia, and weight loss. Treatment is complicated and regarding nutritional support, only a few guidelines are available. Our aim was to critically appraise the literature on nutritional assessment, nutritional status and nutritional support for patients with GVHD-DT. Evidence shows that GVHD-DT is often associated with malnutrition, protein losing enteropathy, magnesium derangements, and deficiencies of zinc, vitamin B 12 and vitamin D. Limited evidence exists on derangements of magnesium, resting energy expenditure, bone mineral density and pancreatic function, and some beneficial effects of n-3 polyunsaturated fatty acids and pancreatic enzyme replacement therapy. Expert opinions recommend adequate amounts of energy, at least 1.5 g protein/kg body weight, supplied by total parenteral nutrition in cases of severe diarrhoea. When diarrhoea is< 500 mL a day, a stepwise oral upgrade diet can be followed. No studies exist on probiotics, prebiotics, dietary fibre and immunonutrition in GVHD-DT patients. Future research should focus on absorption capacity, vitamin and mineral status, and nutritional support strategies.