Undifferentiated lower gastrointestinal bleeding

(Redirected from Lower GI bleeding)

Background

Gasterointestinal anatomy.
Layers of the Alimentary Canal. The wall of the alimentary canal has four basic tissue layers: the mucosa, submucosa, muscularis, and serosa.
  • Loss of blood from the GI tract distal to the ligament of Treitz
  • Must consider upper GI bleed (especially rapid transit) as a source, as a significant number of lower GI bleeds have a concurrent upper GI bleed, brisk or not[2]
  • 80% of lower GI bleeding will resolve spontaneously[3]


Medication Risk Factors

Clinical Features

Type of blood

  • Hematochezia
    • Usually represents lower GI bleeding
    • Left colonic bleeding tends to be bright red, whereas right colonic is usually maroon and mixed with stool[4]
    • May represent upper GI source if bleeding is brisk; usually accompanied by hematemesis and hemodynamic instability
  • Melena
    • Usually represents bleeding from upper GI source (see upper GI bleed)
    • May represent slow bleeding or slow stool transit from lower GI source

Differential Diagnosis

Undifferentiated lower gastrointestinal bleeding

Evaluation

Fecal Occult Blood Test showing positive (A) and positive control (B).
  • Digital rectal exam for guaiac or assessment of anorectal structural abnormalities
    • Note that guaiac tests have low sensitivity, many false positive etiologies (red meat, red jello, certain fruits/veggies, iron), and may not change management clinically
  • Consider chart review to search for prior colonoscopy/endoscopy results

Workup

  • CBC
    • Consider q3-12hr serial Hgb, depending on suspected severity of bleed
    • Initial Hgb may be normal if bleeding is acute
  • CMP
    • BUN may be elevated if bleeding occurs from site high in GI tract, due to heme digestion to nitrogenous substances reflected in BUN[5]
  • Coags
  • Type and screen/cross
  • Consider:
    • CTA; Requires brisk bleeding rate (0.4-0.5 ml/min) for detection[6]
    • Tagged red blood cell scan. This is not typically an emergency study and is only recommended if CTA is unavailable or contraindicated
    • ECG (if concern for silent ischemia in patients likely to have CAD)
    • Fibrinogen

Definitive studies

  • Consider:
    • Anoscopy if source of bleeding cannot be identified on external exam
    • Proctoscopy (22cm from anal verge)
    • Sigmoidoscopy (60cm from anal verge)

Management

  • NPO, if there is foreseeable endoscopy or surgery
  • Fluid resuscitation for all
  • Consider transfusing pRBCs/platelets for unstable patients or with very low hemoglobin (<7). with cardiovascular disease use trigger of 8 and target of 10 hemoglobin.
    • Base decision to transfuse on individual clinical factors. Active bleeding and tachycardia may call for transfusion despite a normal Hgb

Categorize as stable versus unstable using shock index: <1 stable; >1 unstable or suspect active bleeding

  • Unstable
    • CT angiography is preferred for hemodynamically unstable patients due to speed[7]
      • Positive CTA demonstrating extravasation/blush calls for IR consult for transcatheter arteriography and subsequent embolization.
    • Consult GI for emergent colonoscopy, as it is the diagnostic/therapeutic procedure of choice (within 12-24 hours); upper endoscopy may be needed if CTA does not reveal source of GI bleeding
      • Patients with a positive CTA are more likely to have a source found on subsequent colonoscopy
    • Consult surgery if endoscopy and IR embolization fail or are not available
  • Stable
    • See "Disposition"

Major Bleed and Existing Coagulopathy

  • Correct coagulopathy
  • PCC (preferred) or FFP for patients on warfarin
    • Vitamin K 10mg IV (best bioavailability in critical patients)
  • Consider targeted reversal agents for DOACs in life-threatening LGIB refractory to initial resuscitation treatments, if the DOAC was taken in the past 24 hours: See Anticoagulant reversal for life-threatening bleeds
  • Platelets should be administered to thrombocytopenic patients to a goal of 30-50, depending if endoscopy is planned[8]
  • ACG recommends against Tranexamic acid as it has no evidence for benefit but may increase VTE

Special situations

  • Marathon runners - 16% will have hematochezia within 24-48 hrs of race and 85% will be guaiac positive[9]
    • Non-actionable unless abdominal pain present

Disposition

Discharge

  • Oakland score can help determine if outpatient management is feasible; a score of <8 can be considered for safe discharge[10]
    • Based on a recent meta-analysis, the Oakland score, compared to other LGIB risk scores, has good performance in predicting safe discharge, major bleeding, and need for transfusion[11]
  • Bleeding from hemorrhoids, anal fissures, or known IBD (hemodynamically stable)
  • Minor, self-terminating bleed with no other indication for admission (shock index >1; low risk score calculated)

Admission

  • Melena
  • Significant anemia
  • Hemodynamic instability
  • Identified as high risk based on Oakland score

See Also

Gastrointestinal Bleeding Pages

References

  1. Farrell JJ, Friedman LS. Review article: the management of lower gastrointestinal bleeding. Aliment Pharmacol Ther. 2005 Jun 1;21(11):1281-98. doi: 10.1111/j.1365-2036.2005.02485.x. PMID: 15932359.
  2. Amin SK, Antunes C. Lower Gastrointestinal Bleeding. [Updated 2023 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448126
  3. Farrell JJ, Friedman LS. Review article: the management of lower gastrointestinal bleeding. Aliment Pharmacol Ther. 2005 Jun 1;21(11):1281-98. doi: 10.1111/j.1365-2036.2005.02485.x. PMID: 15932359.
  4. Frost J, Sheldon F, Kurup A, Disney BR, Latif S, Ishaq S. An approach to acute lower gastrointestinal bleeding. Frontline Gastroenterol. 2017 Jul;8(3):174-182. doi: 10.1136/flgastro-2015-100606. Epub 2015 Jun 29. PMID: 28839906; PMCID: PMC5558275.
  5. Patel, Sneha MD; Peraza, Jellyana MD; Hasani, Aliaskar MD; Luther, Sanjana MD; Chugh, Rishika MD; Tokayer, Aaron MD, FACG. 611 Finding the Ideal BUN to Creatinine Ratio in an Upper GI Bleed. The American Journal of Gastroenterology 114():p S355, October 2019. | DOI: 10.14309/01.ajg.0000591980.77707.20
  6. Serur A, Rhee R, Ramjist J. Current Nonoperative Therapeutic Interventions for Lower Gastrointestinal Hemorrhage. Clin Colon Rectal Surg. 2020 Jan;33(1):22-27. doi: 10.1055/s-0039-1695033. Epub 2019 Nov 11. PMID: 31915422; PMCID: PMC6946602.
  7. Oakland K, Chadwick G, East JE, et al. Diagnosis and management of acute lower gastrointestinal bleeding: guidelines from the British Society of Gastroenterology. Gut 2019;67:776-789.
  8. Sengupta, N., Feuerstein, J. D., Jairath, V., Shergill, A. K., Strate, L. L., Wong, R. J., & Wan, D. (2023). Management of Patients With Acute Lower Gastrointestinal Bleeding: An Updated ACG Guideline. The American journal of gastroenterology, 118(2), 208–231. https://doi.org/10.14309/ajg.0000000000002130
  9. Sullivan SN, Wong C. Runners' diarrhea. Different patterns and associated factors. J Clin Gastroenterol 1992;14:101-104.
  10. Oakland K, Jairath V, Uberoi R, Guy R, Ayaru L, Mortensen N, Murphy MF, Collins GS. Derivation and validation of a novel risk score for safe discharge after acute lower gastrointestinal bleeding: a modelling study. Lancet Gastroenterol Hepatol. 2017 Sep;2(9):635-643. doi: 10.1016/S2468-1253(17)30150-4. Epub 2017 Jun 23. PMID: 28651935.
  11. Almaghrabi M, Gandhi M, Guizzetti L, et al. Comparison of Risk Scores for Lower Gastrointestinal Bleeding: A Systematic Review and Meta-analysis. JAMA Netw Open. 2022;5(5):e2214253. doi:10.1001/jamanetworkopen.2022.14253