A translation provide by the SITE Intelligence Group indicates the participant is interested in developing a solution that would kill "larger numbers of unbelievers and apostates," the New York Daily News reported Monday.
"I am waiting for the interaction of the experienced brothers to connect the two sciences together and produce a new kind of terrorism, Allah willing," the translation said.
The discussion came after controversy arose over the use of full body scanners and enhanced patdowns at U.S. airports.
Surgically attaching a bomb made of plastic or liquid explosives to an abdominal cavity was considered the best method, the Daily News reported.
"It must be planted near the surface of the body, because the human body absorbs shocks," one forum participant said.
Unproven body cavity bombs concern security agents, although "no one has figured out how to actually do it," a counter-terrorism official told the newspaper.
Last month, Transportation Security Administration chief John Pistole said his agency wouldn't conduct cavity checks because secondary screenings and technology can locate fuses and detonators since they must be located externally.