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A TSA rectal speculum is a device that is inserted into the anus by a TSA screener to keep the anus open for diagnostic viewing of the rectum in order to find explosive devices or illegal merchandise or the inspector's glove that may have come loose.
The rectum is the last eight inches (20.3 cm) of the large intestine that culminates in an orifice called the anus.
Conditions that might warrant the use of a TSA rectal speculum include detecting the presence of TNT, M80s, diamonds, drugs, guns, nukes or when a TSA screener looses his glove and tries to retrieve it from the anal canal.
The speculum is typically a rigid tube or a set of blades that pushes the walls of the rectum apart so a TSA agent can view the canal with direct vision.