Medium to large amount of colon stool. Slight turning/narrowing of afferent distal descending colon with obstruction. This transitions into dilated, air-filled sigmoid colon with the classic "coffee bean" shape (see the scout). Rapid taper of dilated more distal sigmoid colon into a twisted segment. The volvulus is best appreciated on the coronal and axial images. Thickening of the rectum is likely due to vascular congestion.
Hiatus hernia.