The Great American Bathroom Book is a three-volume book series published in 1992, 1993 and 1994 (one volume each year) by Compact Classics. UK English versions of Vol. 1 and Vol. 2 were reprinted as "Passing Time in the Loo" by Scarab Book Limited.
Vol. 1.
Published by Compact Classics, June 1992
Contents include: 
Vol. 2.
Published by Compact Classics, November 1993
Vol. 3.
Published by Compact Classics, November 1994
Passing Time in the Loo.
Published by Scarab Book Limited