Endoscopy 2010; 42: E229-E230
DOI: 10.1055/s-0029-1244119
Unusual cases and technical notes

© Georg Thieme Verlag KG Stuttgart · New York

All that is red is not blood!

A.  Soloman1 , M.  Merheb1 , D.  R.  Ferguson1
  • 1Division of Gastroenterology, MetroHealth Medical Center, Case Western University, Cleveland, Ohio, USA
Further Information

A. Soloman, DO 

Division of Gastroenterology, MetroHealth Medical Center, Case Western University

2500 MetroHealth Dr.
Cleveland
OH 44109
USA

Fax: +1-216-778-4873

Email: asoloman@metrohealth.org

Publication History

Publication Date:
07 October 2010 (online)

Table of Contents

A 62-year-old woman presented for screening colonoscopy after a 24-hour clear-liquid diet and Colyte preparation. Frank blood was noted from the point of colonoscope insertion up to the terminal ileum ([Fig. 1 a]). Aspirate tested negative with the hemoccult card. Using narrow-band imaging (NBI) the “red liquid” appeared cyan blue ([Fig. 1 b]). Upon further questioning during recovery, the patient reported eating red jello.

NBI is an alternative light-wavelength capture system that filters light in the visible spectrum, except for narrow bands in the blue and green wavelengths (415 nm and 540 nm, respectively) [1] ([Fig. 3]). The peak absorption spectrum of red dye is 502 – 518 nm and appears as a cyan color whereas oxyhemoglobin is absorbed at 415 nm and appears as dark maroon. As shown in [Figs. 1 a] and [2 a], red jello and post-polypectomy bleeding appeared indistinguishable under white light. Even the most sophisticated of tools, NBI, has demonstrated here a simple clinical use in differentiating between blood and other red substances. We suspect that this is not the first or the last case of “red jello stool” [2].

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Fig. 1 Screening colonoscopy following ingestion of red jello. a Red liquid in colon lumen seen under white light. b Under the blue light of narrow-band imaging, the red dye in the jello (dye No. 40) appears blue–green.

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Fig. 2 Bleeding from recent polypectomy site. a Seen under white light. b Seen under blue light; note the dark maroon color of the blood.

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Fig. 3 Maximum absorptive capacity of hemoglobin at a wavelength of 415 nm. Adapted with permission from Olympus Europe (www.olympus-europa.com).

Competing interests: None

Endoscopy_UCTN_Code_CPL_1AJ_2AI

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References

A. Soloman, DO 

Division of Gastroenterology, MetroHealth Medical Center, Case Western University

2500 MetroHealth Dr.
Cleveland
OH 44109
USA

Fax: +1-216-778-4873

Email: asoloman@metrohealth.org

#

References

A. Soloman, DO 

Division of Gastroenterology, MetroHealth Medical Center, Case Western University

2500 MetroHealth Dr.
Cleveland
OH 44109
USA

Fax: +1-216-778-4873

Email: asoloman@metrohealth.org

Zoom Image
Zoom Image

Fig. 1 Screening colonoscopy following ingestion of red jello. a Red liquid in colon lumen seen under white light. b Under the blue light of narrow-band imaging, the red dye in the jello (dye No. 40) appears blue–green.

Zoom Image
Zoom Image

Fig. 2 Bleeding from recent polypectomy site. a Seen under white light. b Seen under blue light; note the dark maroon color of the blood.

Zoom Image

Fig. 3 Maximum absorptive capacity of hemoglobin at a wavelength of 415 nm. Adapted with permission from Olympus Europe (www.olympus-europa.com).