Upper and Lower GI Bleeding (Approach and Management)

Risk factors

• UGIB: NSAID/aspirin use, H. pylori, anticoagulants, chronic liver disease/portal hypertension (varices), prior PUD, severe physiologic stress (ICU), alcohol use, smoking
• LGIB: diverticulosis, prior radiation, NSAID use, anticoagulants, vascular disease (mesenteric ischemia), IBD, recent polypectomy or endoscopy, colorectal cancer, hemorrhoids
• Both: age >65, antithrombotic therapy, chronic kidney disease, coagulopathy

Pathophysiology

Bleeding sources reflect underlying mechanisms: erosion of a vessel by acid-peptic injury (PUD), rupture of submucosal varices in portal hypertension, Mallory-Weiss tears, vascular malformations (angiodysplasia, Dieulafoy), diverticular vessel erosion (LGIB), inflammatory or neoplastic ulceration, ischemic injury, and post-procedural bleeding. Hemodynamic compromise depends on volume and rate of bleeding plus patient reserve.

Clinical presentation

Differential diagnosis

• Upper GI bleed: peptic ulcer disease — NSAID use, H. pylori, epigastric pain, melena ± hematemesis; treat with PPI and EGD
• Upper GI bleed: variceal hemorrhage — Cirrhosis or portal hypertension; large-volume hematemesis; octreotide + band ligation + antibiotics
• Upper GI bleed: Mallory-Weiss tear — Vomiting then hematemesis; usually self-limited
• Upper GI bleed: erosive gastritis/esophagitis — Acute illness, NSAIDs, alcohol; diffuse mucosal injury
• Upper GI bleed: Dieulafoy lesion — Submucosal artery, often gastric fundus; recurrent painless bleeding
• Upper GI bleed: aortoenteric fistula — History of aortic graft or AAA; herald sentinel bleed precedes massive hemorrhage
• Upper GI bleed: malignancy (esophageal, gastric) — Weight loss, anemia, chronic blood loss
• Lower GI bleed: diverticular bleeding — Painless brisk hematochezia in elderly; usually right-sided; stops spontaneously in 75%
• Lower GI bleed: angiodysplasia — Painless intermittent bleeding; older adults, CKD, aortic stenosis; right colon
• Lower GI bleed: colitis (ischemic, infectious, IBD) — Diarrhea, abdominal pain, fever; mucosal inflammation on endoscopy
• Lower GI bleed: colorectal neoplasm — Chronic occult or overt bleeding, weight loss, change in bowel habits
• Lower GI bleed: hemorrhoidal/anorectal — Bright red on toilet paper, painless (internal) or painful (thrombosed external)

Diagnostic workup

Diagnostic algorithm

flowchart TD
  A[Suspected GI bleed] --> B[ABCs + 2 large-bore IVs<br/>type and cross, labs, NPO]
  B --> C[Resuscitate with crystalloid<br/>transfuse to Hgb ≥7 g/dL<br/>correct coagulopathy / reverse anticoagulant]
  C --> D{Upper vs lower source?<br/>Hematemesis, melena, BUN:Cr >30 = upper}
  D -->|Upper| E[IV PPI<br/>± octreotide + ceftriaxone if variceal]
  E --> F[EGD within 12-24 h<br/>endoscopic hemostasis<br/>combination therapy for high-risk stigmata]
  F --> G{Hemostasis<br/>achieved?}
  G -->|No| H[Angiographic embolization<br/>or surgery; TIPS for varices]
  G -->|Yes| I[H. pylori test, PPI,<br/>NSAID counseling, beta-blocker if varices]
  D -->|Lower stable| J[Rapid bowel prep<br/>+ colonoscopy ≤24 h]
  J --> K[Endoscopic therapy<br/>treat underlying cause]
  D -->|Lower unstable / brisk hematochezia| L[CTA → angiography<br/>with embolization]
  L --> M{Failed?}
  M -->|Yes| N[Surgical resection<br/>subtotal colectomy if source unknown]

Complications

• Hemorrhagic shock and multiorgan failure
• Aspiration pneumonia
• Rebleeding (UGIB rebleed ~10-20% depending on lesion)
• Myocardial infarction from demand ischemia
• Acute kidney injury
• Transfusion-related reactions, TACO, TRALI
• Hospital-acquired infections
• Death (overall mortality 2-10% UGIB, 2-4% LGIB; higher with variceal hemorrhage and comorbidities)

PANCE pearls

• Resuscitate first, localize later — fluid + blood + correct coagulopathy before endoscopy whenever possible.
• BUN:Cr >30 (without CKD) points to an upper source; do NG lavage only if needed for visualization, not for diagnosis.
• Brisk upper GI bleeding (massive) can present as hematochezia — get EGD first when in doubt with hemodynamic instability.
• Variceal bleed cocktail: octreotide + ceftriaxone + early EGD with band ligation; consider TIPS for refractory bleeding.
• Restrictive transfusion (target Hgb ≥7) improves outcomes in stable UGIB; do not over-transfuse variceal patients (raises portal pressure and worsens bleeding).

References

• ACG 2021 UGIB — ACG Clinical Guideline: Upper Gastrointestinal and Ulcer Bleeding (Laine et al., Am J Gastroenterol 2021)
• ACG 2023 LGIB — ACG Clinical Guideline: Management of Patients with Acute Lower Gastrointestinal Bleeding (Sengupta et al., Am J Gastroenterol 2023)
• AASLD 2017 — AASLD Practice Guidance on Portal Hypertensive Bleeding in Cirrhosis (Garcia-Tsao et al., Hepatology 2017/2024 update)
• ESGE 2021 — European Society of Gastrointestinal Endoscopy guideline: diagnosis and management of non-variceal upper GI hemorrhage