This poem describes the ineffable experience of

having a barium enema to answer the question, "has time betrayed you yet?" While it is summer outside, inside the room "numbers flee across / banked screens." The narrator tries not to be there, but he is. Soon he will "pass a gallon, / more or less, of latex enamel, / as blooms of cramp go on and on." He sees the barium as it moves through the compartments of his large intestine, and he reflects that "life is so common"--but not his life.