An artifact is clearly visible in the VRT image (see red circle, on image 1). It is a motion artifact, but on the same level no other artifacts can be immediately seen. The pelvic bone doesn’t show any motion. So, “real” patient motion can be excluded indicating that the motion comes from inside the colon. Check the marked area (see green circle on image 2) of the colon wall where a lack of sharpness can be detected. Clearly, some motion can be seen there, after adapting the window width and level. As it is at the same z-position we can say that the motion is caused by flatulation during the examination.