In the January 2021 issue of BMC Gastroenterology, Elmokadem et al. report their findings on the use of gastric ultrasound (GUS) for the evaluation of feeding intolerance—defined as high gastric residual volume—in critically ill patients. We voice in this correspondence our concerns regarding certain methodological flaws and believe the study results should be interpreted with caution. The authors applied a model unvalidated for non-clear fluids as enteral feeding, the scanning protocol was not clearly described and essential anatomical landmarks required for correct interpretation are not visible in the presented images. Additionally, since GUS was not compared to a gold standard, we believe the authors’ conclusion may be overoptimistic and does not undoubtedly answer the primary outcome.