shy bowel
n.— «Parcopresis is the phobia assigned to those who absolutely cannot do number two in a public restroom. This phobia is also termed as “shy bowel” because the sufferer, your date, must have a certain level of privacy before their mind will let their behind “let loose.”» —“Public restroom phobia cripples dating” by Michele Gwynn Examiner.com Aug. 20, 2009. (source: Double-Tongued Dictionary)