Opinion by Judge BEEZER; Concurrence by Judge KOZINSKI; Dissent by Judge D.W. NELSON

Elizabeth Gonzalez-Rincon (“Gonzalez”) appeals from the judgment entered upon her conviction for possession of cocaine with intent to distribute, 21 U.S.C. § 841 (a)(1), and importation of cocaine, 21 U.S.C. §§ 952 (a) and 960. She argues that the district court erred in denying her motion to suppress cocaine seized after she was detained at the border for a monitored bowel movement. She also argues that the district court erred in denying her motion for a new trial, based on the government’s failure to disclose impeachment evidence prior to trial, and in refusing to admit into evidence her husband’s death certificate. We have jurisdiction pursuant to 28 U.S.C. § 1291 , and we affirm.

I

On March 10, 1993, Gonzalez arrived at Los Angeles International Airport on a flight from Bogota, Colombia, via Mexico City. A United States Customs inspector monitoring incoming passengers noticed Gonzalez because she was wearing a bulky overcoat, unlike other passengers on her flight, and was carrying only one piece of luggage and a purse. When questioned, Gonzalez stated that she was from Colombia and was visiting the United States for 15 days. She was then referred to a secondary customs examination.

A second customs inspector requested Gonzalez’s passport, customs declaration form and airline ticket. Her passport and declaration form were in the name “Aurieste-la Davilla de Ravachi” and the declaration form listed an address of 15755 Pocono Street in La Puente, California. The inspector noted that Gonzalez purchased her ticket with cash on March 5, 1993 for a flight on March 5 and that her passport reflected numerous entries into the United States. He also noted that she was perspiring profusely and appeared nervous.

When asked her profession, Gonzalez stated that she was a portrait photographer. She could not, however, describe the type of camera she used other than to say that it was a “very big” Canon that used 35 millimeter film. She produced a laminated card indicating she was a media photographer but she carried only a small pocket camera. When asked why she came to the United States, she first stated that she was here to attend her sister’s wedding. Later, however, Gonzalez stated that her sister was already married and that she was here to help with her sister’s children. She did not have her sister’s telephone number, and her sister did not meet her at the airport.

Based on this interview and on a search of her luggage, the Customs inspectors decided to conduct a patdown search and a partial strip search of Gonzalez to determine if she was carrying narcotics. During the strip search, the inspectors instructed Gonzalez to perform several knee squats and felt her groin area through her underwear to determine if she was concealing drugs. None were found. At the inspectors’ request, Gonzalez consented to be x-rayed. She was handcuffed and transported to an airport hospital, where she was given a urine test that indicated she was pregnant. The attending physician advised that Gonzalez not be x-rayed. She was then detained for a monitored bowel movement.

After several hours and attempts at bowel movements, Gonzalez reported that she had passed blood. The physician examined Gonzalez’s anal cavity and felt a hard object. Gonzalez then confessed that she was carrying cocaine in her rectum and alimentary canal and signed a consent form permitting the physician to remove from her rectum two blue cylinder-shaped objects containing cocaine. She eventually expelled 73 balloons of cocaine. In total, Gonzalez smuggled 1005 grams of cocaine in her rectum and alimentary canal.

Gonzalez moved to suppress the cocaine, arguing that the inspectors lacked reasonable suspicion to conduct the strip search and to detain her for monitored bowel movements. The district court denied the motion.

*862 Gonzalez’s trial commenced on June 1, 1993. On June 2, Gonzalez took the stand and claimed duress. She testified that her husband had been murdered in July 1992, that he owed a debt to his murderers, and that his murderers threatened to kill Gonzalez’s children if she did not smuggle cocaine into the United States to repay her husband’s debt. She testified that the alleged murderers contacted her for the first time in December 1992 and that she received the passport in the name of Auriestela Davilla de Ravachi for the first time in March 1993, shortly before her trip to the United States.

Following Gonzalez’s testimony on direct examination, prosecutors obtained copies of computer records from an Immigration and Naturalization Service (“INS”) agent revealing that a person using a passport in the name of Auriestela Davilla de Ravachi had entered the United States through Los An-geles on November 20, 1992, and had completed a declaration form with the address of 15755 Pocono Street in La Puente, California. The prosecutors discovered that a customs inspector had been in possession of the declaration form since at least March 1993. They obtained the form from him on June 3. The government then disclosed the form to Gonzalez’s defense counsel.

On the following day, June 4, Gonzalez stated under cross-examination that she did not enter the United States using the name “Auriestela Davilla de Ravachi,” or any other name, on November 20, 1992. In rebuttal, the government moved to admit the November 20, 1992 declaration form and called as witnesses the INS agent and a handwriting expert to establish that the form had been completed by a person with handwriting identical to that of Gonzalez. Gonzalez objected to the document’s admission under Rule 16 of the Federal Rules of Criminal Procedure. Her objection was overruled.

On the afternoon of June 3, at the government’s request and in the presence of defense counsel, the INS agent conducted an infrared examination of the passport Gonzalez had used during her March 1993 entry. On June 4, the agent testified that when the passport was placed under a black light, illumination of the ink used on an INS entry stamp revealed that the stamp had been altered to read November 20,1990. Defense counsel sought a continuance to prepare for the witness’ cross examination and to consult an infrared expert. The district court denied the request.

During redirect examination of Gonzalez, her counsel attempted to introduce her husband’s death certificate to establish the cause, date and time of his death. The government objected to the certificate’s admission on the grounds that it lacked authentication and foundation, and contained hearsay. The district court sustained the objection on the basis that questions regarding the death certificate, which was not offered into evidence on Gonzalez’s direct examination, were not proper on redirect.

Gonzalez moved for a new trial, arguing that the government had violated Rule 16 of the Federal Rules of Criminal Procedure by failing to disclose to her the impeachment evidence until the day before its admission at trial. She also argued that the district court erred in denying her request for a continuance and in refusing to admit the death certificate. The district court denied her motion. Gonzalez timely appealed.

II

Gonzalez argues that her detention for monitored bowel movements constituted an unreasonable search and seizure under the Fourth Amendment because the customs inspectors lacked reasonable suspicion that she was an alimentary canal smuggler. She argues that the inspectors’ failure to find evidence of drugs during her strip search should have allayed their suspicions, rather than have given rise to suspicion of internal smuggling. Gonzalez contends that reasonable suspicion of alimentary canal smuggling could be found only if certain additional factors were present in her case that supported reasonable suspicion in other cases. See, e.g., United States v. Oba, 978 F.2d 1123, 1126 (9th Cir.1992) (defendant possessed an-tidiarrheal and motion sickness medication); United States v. Chukwubike, 956 F.2d 209, 210 (9th Cir.) (antidiarrheal medicine), cert. denied, — U.S. -, 112 S.Ct. 2288 , 119 *863 L.Ed.2d 212 (1992); United States v. Handy, 788 F.2d 1419, 1420 (9th Cir.1986) (lubricant, dental floss and anti-laxative); see also United States v. Montoya de Hernandez, 473 U.S. 531, 534 , 105 S.Ct. 3304, 3306 , 87 L.Ed.2d 381 (1985) (during strip search inspector felt abdomen area and noticed firm fullness; also, defendant was wealing two pairs of elastic underpants with paper towel in crotch). She also argues that without such additional factors, her detention was based on no more than classic drug courier profile factors, insufficient to support reasonable suspicion. See United States v. Rodriguez, 976 F.2d 592 (9th Cir.1992), amended, 997 F.2d 1306 (1993).

We review de novo whether a border detention is based on reasonable suspicion. Oba, 978 F.2d at 1128 . We accept the district court’s findings of fact unless they are clearly erroneous. Id. at 1125 . When evaluating a border search, we view “as a whole all factors that would be considered by an experienced and prudent customs inspector.” Handy, 788 F.2d at 1421 . Detention for a monitored bowel movement is justified if customs officers have a “particularized and objective basis for suspecting the particular person of alimentary canal smuggling.” Oba, 978 F.2d at 1128 (internal quotations omitted).

The following facts were known to the customs inspectors when they detained Gonzalez for an x-ray and monitored bowel movements: Gonzalez was traveling from a known “source city” for narcotics. She paid cash for her ticket, which was purchased on the day of the flight, and carried only one piece of luggage despite stating that she planned to stay in the United States for 15 days. She gave inconsistent explanations for the purpose of her trip and an implausible description of her occupation. She presented a passport reflecting several entries into the United States. She also appeared nervous and perspired heavily throughout the interview.

Based on these facts, the customs inspectors possessed reasonable suspicion of drug smuggling sufficient to support a detention for monitored bowel movements.

We specifically reject Gonzalez’s contention that the customs officers justified her detention on no more than a mere incantation of classic courier profile evidence. The customs inspectors based their suspicion on several factors they learned through interviewing her that were not consistent with innocent travel. These factors include her nervous demeanor and her lies about the purpose of her trip and her occupation, which are not easily susceptible to rote profile recitations. See United States v. Rodriguez-Sanchez, 23 F.3d 1488, 1493 (9th Cir.1994).

We also reject Gonzalez’s argument that the customs inspectors needed additional factors to reasonably suspect that she was smuggling narcotics in her alimentary canal. That the facts of this case differ from those of other cases in this circuit is not conclusive. “[0]ur duty is to look at the totality of the circumstances of each ease.” Oba, 978 F.2d at 1128 (citation omitted). Although possession of certain paraphernalia or other indications of internal smuggling are persuasive factors, they are not necessary to support reasonable suspicion of alimentary canal smuggling. The ingestion of drug-filled balloons has become a “common smuggling device” for smugglers from countries such as Colombia, a principal source of illicit narcotics. United States v. Reyes, 821 F.2d 168, 168-69 (2d Cir.1987), cert. denied, 484 U.S. 1068 , 108 S.Ct. 1032 , 98 L.Ed.2d 996 (1988). Alimentary canal smuggling “appears to be a relatively recent addition to the smugglers’ repertoire of deceptive practices, and it also appears to be exceedingly difficult to detect.” Montoya de Hernandez, 473 U.S. at 538 , 105 S.Ct. at 3308 . Once an experienced customs officer reasonably suspects that a traveler is smuggling narcotics, failure to find that she is carrying the drugs externally may give rise to suspicion that she is carrying them in her rectum or alimentary canal. See United States v. Onumonu, 967 F.2d 782, 789 (2d Cir.1992) (evidence that defendant was nervous, sweating profusely, traveling from a source country and declined to be x-rayed was sufficient to establish reasonable suspicion of alimentary canal and rectal smuggling); United States v. Oyekan, 786 F.2d 832, 834 (8th Cir.1986) (even though strip *864 search revealed no evidence of drugs or paraphernalia associated with alimentary canal smuggling, reasonable suspicion supported detention for x-ray and monitored bowel movements of two women from source country who carried small amount of luggage, paid cash for tickets and told implausible stories about their purpose for traveling to the United States).

Our decision is influenced by the fact that Gonzalez’s search took place at our nation’s border, which holds a special place in Fourth Amendment jurisprudence “ ‘pursuant to the longstanding right of the sovereign to protect itself by stopping and examining persons and property crossing into this country.’ ” United States v. Sandoval Vargas, 854 F.2d 1132, 1134 (9th Cir.) (quoting United States v. Ramsey, 431 U.S. 606, 616 , 97 S.Ct. 1972, 1978 , 52 L.Ed.2d 617 (1977)), cert. denied, 488 U.S. 912 , 109 S.Ct. 270 , 102 L.Ed.2d 257 (1988). Congress has conferred broad authority on customs officers to search all persons coming into the United States from foreign countries. 19. U.S.C. § 1582; see 19 C.F.R. § 162.6 (1993). 1 A traveler crossing an international boundary may reasonably be required “to identify himself as entitled to come in, and his belongings as effects which may be lawfully brought in.” Carroll v. United States, 267 U.S. 132, 154 , 45 S.Ct. 280, 285 , 69 L.Ed. 543 (1925). Thus, at the border one’s expectation of privacy is less than in the interior and the Fourth Amendment balance between the government’s interests and the traveler’s privacy rights is “struck much more favorably to the Government.” Montoya de Hernandez, 473 U.S. at 539-40 , 105 S.Ct. at 3309 (citations omitted).

Routine searches of persons at the border “are not subject to any requirement of reasonable suspicion, probable cause or warrant.” Id. at 538 , 105 S.Ct. at 3309 ; see 19 C.F.R. § 162.6 . Such searches are deemed reasonable under the Fourth Amendment ‘“by the single fact that the person or item in question has entered into our country from outside.’ ” Sandoval Vargas, 854 F.2d at 1134 (quoting Ramsey, 431 U.S. at 619 , 97 S.Ct. at 1980 ). Because “a port of entry is not a traveler’s home ... [h]is right to be let alone neither prevents the search of his luggage nor the seizure of unprotected, but illegal, materials when his possession of them is discovered.” United States v. Thirty-Seven Photographs, 402 U.S. 363, 376 , 91 S.Ct. 1400, 1408 , 28 L.Ed.2d 822 (1971). Strip searches and body-cavity searches are of course considered nonroutine, and, unlike luggage searches and patdowns, must be supported by reasonable suspicion. Montoya de Hernandez, 473 U.S. at 541 , 105 S.Ct. at 3310 . Once customs officials reasonably suspect that an international traveler is smuggling contraband, however, they may detain her and perform the searches necessary to either verify or dispel the suspicion that she “will introduce a harmful agent into this country.” Id. at 544 , 105 S.Ct. at 3312 .

The customs inspectors reasonably suspected Gonzalez of attempting to smuggle narcotics across our nation’s border. They were permitted under the Fourth Amendment to conduct a reasonable search to either verify or dispel their suspicion. The scope of this search included detaining her for an x-ray or for monitored bowel movements as necessary. Because Gonzalez’s detention did not violate the Fourth Amendment, the district court properly denied her motion to suppress. 2

Ill

Gonzalez argues that the government violated Rule 16 of the Federal Rules of Crimi *865 nal Procedure by failing to disclose to her the November 20, 1992 customs declaration form until the day before it was introduced as rebuttal evidence at trial.

Upon the defendant’s request, the government must disclose to her “any relevant written or recorded statements made by the defendant” or any documents “material to the preparation of the defense” that are “within the possession, custody, or control of the government, the existence of which is known, or by the exercise of due diligence may become known, to the attorney for the government.” Fed.R.Crim.P. 16(a)(1)(A), (C). The prosecutor is “deemed to have knowledge of and access to anything in the possession, custody or control of any federal agency participating in the same investigation of the defendant.” United States v. Bryan, 868 F.2d 1032, 1036 (9th Cir.), cert. denied, 493 U.S. 858 , 110 S.Ct. 167 , 107 L.Ed.2d 124 (1989). We review the district court’s discovery rulings under Rule 16 for an abuse of discretion and its legal construction of the rule de novo. United States v. Mandel, 914 F.2d 1215, 1219 (9th Cir.1990). To prevail on appeal, Gonzalez must show not only that the district court abused its discretion, but that the abuse resulted in prejudice to her substantial rights. See United States v. Michaels, 796 F.2d 1112, 1115 (9th Cir.1986), ce rt. denied, 479 U.S. 1038 , 107 S.Ct. 893 , 93 L.Ed.2d 845 (1987).

The relevance of the customs declaration form was inextricably tied to Gonzalez’s duress defense. Specifically, the form was relevant to her statements that the men who allegedly coerced her to smuggle cocaine contacted her for the first time in December 1992 and did not give her the passport in the name of Auriestela Davilla de Ravachi until March 1993. Because the declaration form was offered only as impeaching evidence after Gonzalez testified, it was not a “relevant statement” within the meaning of Rule 16. See United States v. Bailleaux, 685 F.2d 1105, 1114 (9th Cir.1982); see also United States v. Gleason, 616 F.2d 2, 25 (2d Cir.1979), ce rt. denied, 444 U.S. 1082 , 100 S.Ct. 1037 , 62 L.Ed.2d 767 , and cert. denied sub nom. Carter v. United States, 445 U.S. 931 , 100 S.Ct. 1320 , 63 L.Ed.2d 764 (1980) (“The Government is not obligated by Rule 16(a) to anticipate every possible defense, assume what the defendant’s trial testimony ... will be, and then furnish him with otherwise irrelevant material that might conflict with his testimony.”). The district court did not abuse its discretion in admitting the declaration on rebuttal. 3

IV

Gonzalez also contends that the district court erred in denying her motion for a continuance when the government introduced results of an infrared test to establish that the INS entry stamp on the passport she used had been altered to conceal the November 20, 1992 entry.

“The decision to grant or deny a requested continuance lies within the broad discretion of the district court, and will not be disturbed on appeal absent clear abuse of that discretion.” United States v. Flynt, 756 F.2d 1352, 1358 , amended, 764 F.2d 675 (9th Cir.1985). “To reverse a trial court’s denial of a continuance, an appellant must show that the denial prejudiced [her] defense.” United States v. Lewis, 991 F.2d 524, 528 , amended, (9th Cir.), cert. denied, — U.S. -, 114 S.Ct. 216 , 126 L.Ed.2d 172 (1993). She must also set forth the substance of the witness testimony she could have obtained if given more time. Id.

Gonzalez argues that because the infrared test results were inculpatory evidence that adversely affected her defense, the district court should have granted a continuance so that her attorneys could prepare cross-examination and find an expert witness. She does not, however, establish the substance of any expert testimony she may have obtained had the district court granted her request for a continuance. See United States v. Lane, 765 F.2d 1376, 1379 (9th Cir.1985). The only prejudice Gonzalez can establish, moreover, *866 is that the infrared evidence was admitted to demonstrate that she lied about her entry into the United States. The district court did not abuse its discretion in denying the motion for a continuance.

V

Gonzalez argues that the district court erred in refusing to admit into evidence her husband’s death certificate.

We review the district court’s evidentiary rulings for an abuse of discretion. United States v. Segall, 833 F.2d 144, 148 (9th Cir.1987). We will reverse “for nonconstitutional error only if it was more probable than not that the error affected the verdict.” United States v. McAllister, 747 F.2d 1273, 1277 (9th Cir.1984), cert. denied, 474 U.S. 829 , 106 S.Ct. 92 , 88 L.Ed.2d 76 (1986).

On direct examination, Gonzalez testified that she was coerced into smuggling the cocaine by men who murdered her husband, Jimeno. On cross examination, the government asked Gonzalez the date of her husband’s death. She could not remember the exact date. On redirect, defense counsel attempted to introduce into evidence the death certificate of someone with the name “Jimeno Hernandez Valderrama.” The certificate contained information about the date, time, place and causes of death. The district court refused to admit the certificate, concluding that it was improper evidence on redirect examination because the exact date of Jimeno’s death was irrelevant and questioning regarding the death certificate did not affect Gonzalez’s credibility.

We may affirm the district court’s decision on any basis supported by the record. United States v. Washington, 969 F.2d 752, 755 (9th Cir.1992), cert. denied, — U.S. -, 113 S.Ct. 1945 , 123 L.Ed.2d 651 (1993). Although the government concedes that the document was properly authenticated, it argues that no foundation was laid for the certificate’s admission. We agree. Gonzalez offered no evidence to establish that the person named in the death certificate was her husband. Gonzalez has failed to persuade us, moreover, that the certificate’s omission more probably than not affected the verdict. Accordingly, the judgment of the district court is

AFFIRMED.

. Much has been made of the fact that the first customs statute, Act of July 31, 1789, ch. 5, 1 Stat. 29 , 43, which permitted the warrantless search of vessels on the mere suspicion of illegal importation of goods, was enacted by the same Congress that proposed the adoption of the Fourth Amendment, thus indicating “that the members of that body did not regard searches and seizures of this kind as 'unreasonable,' and they are not embraced within the prohibition of the amendment." Boyd v. United States, 116 U.S. 616, 623 , 6 S.Ct. 524, 528 , 29 L.Ed. 746 (1886); see also United States v. Ramsey, 431 U.S. 606, 616-17 , 97 S.Ct. 1972, 1978-79 , 52 L.Ed.2d 617 (1977).

. Our holding that the facts supported reasonable suspicion of alimentary canal smuggling naturally subsumes Gonzalez's argument that the inspectors lacked reasonable suspicion to perform a strip search. We therefore do not consider this argument separately.

. Even if the evidence was material to Gonzalez's defense, she has failed to demonstrate that its admission violated her substantial rights. The evidence was offered as rebuttal to Gonzalez’s own testimony and any prejudice resulted from her own false statements. Gonzalez has no substantial right to commit peijury.