Lower GI Bleeds: Risk factors Portal
Esophageal varices (large veins in the esophagus that are at risk for bleeding)
Rectal varices (large veins in the rectum that are at risk for bleeding)
Splenomegaly (enlargement of the spleen)
Large spleen sequesters (traps) platelets, reducing blood platelet counts
↓ Clotting ability of the blood
↓ Epithelial protection along entire GI tract
Pre-existing damage to the lower GI tract epithelium
Malignant tissue invades the colon wall and disrupts colonic blood vessels
New, extremely friable blood vessels develop within the tumor
Venous blood pressure exceeds vessel wall strength, and the vessel ruptures and bleeds
Blood moves rapidly through the GI tract (this is an upper GI bleed that can produce lower GI bleed symptoms)
Hematochezia
(bright red blood per rectum)
Damaged liver tissue restricts
blood flow through liver
hypertension (high blood pressure in the veins running from the GI tract to the liver)
Blood backs up in the splenic vein
Venous blood pressure exceeds vessel wall strength, and the vessel ruptures and bleeds
Liver cirrhosis
Authors: Yan Yu, Miranda Schmidt Illustrator: Mizuki Lopez Reviewers: Michael Blomfield, Tony Gu, Jason Baserman, Jennifer Au, Vina Fan, Ben Campbell, Kerri Novak* * MD at initial time of publication
↓ Synthesis of blood clotting factors that are normally produced in the liver (i.e. fibrinogen)
Bleeding of capillaries under the skin
Petechiae
(small red dots on skin)
Inferior Vena Cava
Blood clotting defect (genetic disorder, Acetylsalicylic Acid use)
Non-Steroidal Anti- Inflammatory Drug (NSAID) Use
Prior lower GI bleeds
Family history of colorectal cancer
Diaphragm
Esophagus
↓ Systemic prostaglandin synthesis
↑ Risk for lower GI bleed
↑ Risk for colorectal cancer
Development of colorectal cancer
Duodenum
Ligament of Treitz
Lower GI Bleeds are intra-luminal GI tract bleeds that occur anywhere distal to the ligament of Treitz (transition between duodenum and jejunum)
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Re-Published June 30, 2019, updated August 15, 2022 on www.thecalgaryguide.com