Colon nontumor
Nonneoplastic, noncongenital lesions
Blue / green / red colon

Topic Completed: 1 August 2013

Revised: 9 January 2019, last major update August 2013

Copyright: (c) 2003-2017,, Inc.

PubMed Search: blue colon, green colon, red colon

Raul S. Gonzalez, M.D.
Page views in 2019: 193
Page views in 2020 to date: 76
Cite this page: Gonzalez R. Blue / green / red colon. website. Accessed May 26th, 2020.
Definition / general
  • Unusual gross pigmentation of the colon, typically observed at autopsy
  • Also known as abnormal pigmentation of organs
  • Anywhere in the gastrointestinal tract, including stomach, duodenum and colon
  • Due to pigments such as those in foods, food coloring or pharmaceutical drugs; may result from enteral feeding solutions containing these pigments
Clinical features
  • Patients may have similarly colored feces; food coloring is used to identify either aspirated gastric contents in suctioned airway fluids or the source of fistulous drainage
  • All case reports have diagnosed findings at autopsy; cause of death was unrelated to colonic finding
Case reports
Gross description
  • Colonic mucosa and serosa diffusely stained with abnormal pigment; other gastrointestinal organs may show similar coloration
Gross images

Images hosted on other servers:

Green colon

Blue colon

Blueish red colon (Fig 3)

Microscopic (histologic) description
  • Colon normal microscopically, as pigment usually washes away or otherwise does not survive processing
Differential diagnosis
  • Melanosis coli: colon mucosa is black, not blue / green / red, serosa is unpigmented and pigment is observable microscopically
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