Chart — Gastrointestinal
Upper vs Lower GI Bleeding
Comprehensive side-by-side comparison of upper and lower GI bleeding — anatomical sources, clinical presentations, diagnostic approaches, and treatment priorities.
Educational use only. This content is intended for nursing students and exam preparation. Clinical decisions require licensed professional judgment and institutional protocols. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Upper GI Bleeding (UGIB)
Source proximal to ligament of Treitz
Melena • Hematemesis • Elevated BUN:Cr
Lower GI Bleeding (LGIB)
Source distal to ligament of Treitz
Hematochezia • Normal BUN:Cr • No emesis
| Feature | Upper GI Bleeding | Lower GI Bleeding |
|---|---|---|
| Anatomical source | Proximal to ligament of Treitz: esophagus, stomach, duodenum | Distal to ligament of Treitz: small bowel, colon, rectum, anus |
| Stool finding | Melena (black, tarry, foul-smelling) — blood altered by gastric acid and bacterial oxidation | Hematochezia (bright red or maroon blood per rectum) — blood exits before full oxidation |
| Vomiting | Hematemesis (bright red blood) or coffee-ground emesis (partially digested blood) | Typically absent; if present, indicates upper source or large-volume lower bleed |
| BUN:Creatinine ratio | >20:1 — blood digested as dietary protein → raises BUN selectively | Normal ratio (~10:1) — blood not significantly absorbed as protein from colon |
| Most common causes | Peptic ulcer disease (PUD) #1; esophageal/gastric varices; Mallory-Weiss tear; esophagitis/gastritis | Diverticulosis #1 (adults >50); colorectal cancer; angiodysplasia; IBD; hemorrhoids; ischemic colitis |
| Variceal bleeding | Yes — esophageal and gastric varices from portal hypertension (cirrhosis). Life-threatening. | No — anorectal varices (hemorrhoids) are low-pressure, rarely cause significant hemorrhage |
| Hemodynamic instability | More common — varices and PUD can cause massive arterial hemorrhage | Less common overall — but diverticular and angiodysplastic bleeds can be massive |
| Primary diagnostic test | EGD (Esophagogastroduodenoscopy) — within 24 hrs after presentation; resuscitate/stabilize first (very-early <12 hr EGD not recommended); identifies source and allows therapy | Colonoscopy — diagnostic/therapeutic standard for LGIB; 2023 ACG recommends NONEMERGENT inpatient colonoscopy (urgent <24 hr does NOT improve rebleeding or mortality); for stable patients, within 14 days of hemostasis is acceptable. Hemodynamically unstable/ongoing brisk bleeding → resuscitate first; consider CT angiography/IR |
| Backup diagnostic test | CT angiography (active bleeding ≥0.3 mL/min); tagged RBC scan | CT angiography (active bleeding ≥0.3 mL/min); capsule endoscopy (small bowel source) |
| Endoscopic treatment options | Epinephrine injection, thermal coagulation, clipping, band ligation (varices), hemostatic powder | Epinephrine injection, thermal coagulation, clipping, polypectomy, band ligation (hemorrhoids) |
| Pharmacologic treatment | IV PPI infusion (ulcer bleed); IV octreotide (variceal bleed); IV antibiotic prophylaxis (variceal bleed) | No specific pharmacologic agent for active LGIB; treat underlying cause (steroids for IBD, etc.) |
| Interventional radiology | Embolization for arterial bleeding not controlled by endoscopy; TIPS for recurrent variceal bleed | Super-selective embolization for active diverticular or angiodysplastic bleed |
| Surgical intervention | Rare — for refractory bleeding or perforated PUD; balloon tamponade as bridge for varices | Reserved for failed endoscopy/IR, massive hemorrhage requiring massive transfusion, cancer resection |
| Rebleed risk | High for varices (70% without prophylaxis), moderate for ulcers (10–20% with therapy) | Varies — diverticular bleeds stop spontaneously in 75–80%; angiodysplasia has higher recurrence |
| Key NCLEX distinction | Elevated BUN:Cr ratio + melena/hematemesis = upper source. Octreotide = varices. PPI = ulcers. | Normal BUN:Cr + hematochezia = lower source. Colonoscopy = gold standard. Diverticulosis = #1 cause in adults. |
Universal First Steps — Both Upper & Lower GI Bleeding
Source: ACG Clinical Guidelines for GI Hemorrhage; UpToDate; ASGE Standards of Practice
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with ACG Clinical Guidelines for GI Hemorrhage; ASGE Standards of Practice; UpToDate. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →