Background: Acute gastric dilatation can develop in patients with anorexia nervosa who are being refed to achieve weight restoration. If unrecognized, this condition is associated with significant morbidity and mortality. Patients with acute gastric dilatation usually have abdominal pain, nausea, and vomiting. Abdominal imaging confirms the diagnosis. This study aims to identify risk factors associated with the development of acute gastric dilatation in patients with severe restrictive eating disorders in order to hasten diagnosis and guide treatment. This study also aims to define the clinical outcomes of patients with acute gastric dilatation. Methods: In this retrospective case series, 15 patients with a restrictive eating disorder were studied. Multiple variables were assessed for significant correlation with stomach size. Results: 15 patients with a restrictive eating disorder were identified as being diagnosed with acute gastric dilatation through chart review during the study period. The average dilated stomach size was 20.5 cm. There was no significant correlation of stomach size with any of the following: % ideal body weight on day of admission, % ideal body weight on day of imaging study, rate of weight gain (kg per week), or duration of illness. Serum levels of sodium, potassium, phosphorus, magnesium, calcium, bicarbonate, blood urea nitrogen, glucose, albumin, and hematocrit on the day of imaging, did not correlate with stomach size. All patients were treated with conservative management. None of the patients required surgical intervention or progressed to gastric necrosis or perforation, and there were no recurrences of the acute gastric dilatation. Conclusions: There are no specific risk factors significantly associated with the development of acute gastric dilatation in patients with severe restrictive eating disorders. Clinicians should maintain a high index of suspicion for this condition when patients are experiencing abdominal pain, nausea, or vomiting. When promptly diagnosed and treated, outcomes are good. If diagnosis is delayed, the outcome can be dire. Plain English summary: The mainstay of treatment of patients with severe restrictive eating disorders is initiation of nutrition to gain weight. One potential complication when patients are started on nutrition is the development of a massively enlarged stomach, also called acute gastric dilatation. If a patient's care provider does not recognize the development of acute gastric dilatation, it can lead to serious problems, including death. Patients with this condition usually have abdominal pain, nausea, and vomiting. These are common symptoms in patients with anorexia nervosa and are often dismissed. Identifying risk factors associated with developing acute gastric dilatation could help providers recognize this condition and promptly start treatment. This study sought to identify risk factors associated with developing acute gastric dilatation in patients with severe restrictive eating disorders. Several variables, including patient age, duration of illness, body mass index, %ideal body weight, laboratory values, medications, type of nutrition, and rate of weight gain were analyzed. This study found that there are no specific risk factors significantly associated with development of acute gastric dilatation in patients with severe restrictive eating disorders being initiated on nutrition. Therefore, providers need to listen to their patients, evaluate symptoms, and have a high index of suspicion for underlying acute gastric dilatation. [ABSTRACT FROM AUTHOR]