It was a bad weekend for bodily-function comedy. “Hall Pass,” the latest from Bobby and Peter Farrelly, was expected by movie analysts to top the North American box office with about $20 million in sales. But it fizzled in second place. Instead, the animated “Gnomeo & Juliet” (Walt Disney Pictures) (the lovers, above) rose to No. 1 in its third weekend with an estimated $14.2 million, bringing its total to about $75 million, according to Hollywood.com, which compiles box-office statistics. “Hall Pass,” starring Owen Wilson and Jason Sudeikis and filmed at a cost of about $35 million by New Line Cinema, sold $13.4 million, becoming the latest in a string of disappointments from the Farrelly brothers. The Liam Neeson thriller “Unknown” (Warner Brothers) sold an estimated $12.4 million for a two-week total of $42.8 million. Adam Sandler’s “Just Go With It” (Sony Pictures Entertainment) was fourth with about $11.1 million, lifting its three-week total to $79.4 million. “I Am Number Four,” a teenage science-fiction thriller from DreamWorks Studios, rounded out the top five with about $11 million for a two-week total of $37.7 million.