GI NOTES

Upper and Lower GI Bleeding

1. Definitions and presentation

Type	Source	Typical presentation
Upper GI bleed (UGIB)	Proximal to the ligament of Treitz (esophagus, stomach, duodenum)	Hematemesis, coffee-ground emesis, melena. Hematochezia if bleeding is brisk (about 10 to 15 percent of hematochezia is a severe UGIB).
Lower GI bleed (LGIB)	Distal to the ligament of Treitz; most are colonic or anorectal	Hematochezia, maroon stool. Melena is possible with right-sided or small bowel sources.
Small bowel (“mid”) bleed	Between the ampulla and terminal ileum; about 5 to 10 percent of GI bleeds	Occult or overt bleeding after a negative EGD and colonoscopy

Clues that favor an upper source: melena, hematemesis, BUN to creatinine ratio above 30, history of ulcer, NSAID or anticoagulant use, cirrhosis, or an aortic graft. Warning sign: hematochezia with hypotension or tachycardia is an upper source until proven otherwise.

2. Initial assessment (both upper and lower)

1. Hemodynamics: heart rate, blood pressure, orthostatics, shock index (heart rate divided by systolic pressure; 1 or higher is concerning). Place two large-bore IVs.
2. Airway: consider intubation before endoscopy for massive hematemesis, altered mental status, or inability to protect the airway.
3. Labs: CBC, BMP with BUN, INR, type and screen, lactate, liver tests. The initial hemoglobin can be falsely normal in acute bleeding.
4. Medication review: anticoagulants, antiplatelets, NSAIDs, SSRIs, iron or bismuth (can mimic melena).
5. History: prior bleeds, ulcers, cirrhosis, varices, alcohol, aortic surgery, radiation, IBD, polypectomy within 14 days, recent colonoscopy.
6. Exam: stigmata of liver disease, abdominal exam, and a rectal exam to confirm stool color.

3. Risk stratification

Score	Use	Components	Action threshold
Glasgow-Blatchford (GBS)	UGIB: who can go home	BUN, hemoglobin (by sex), systolic BP, heart rate, melena, syncope, liver disease, heart failure	GBS 0 to 1 is very low risk and can be managed as an outpatient with follow-up.
AIMS65	UGIB: predicts in-hospital mortality	Albumin below 3, INR above 1.5, altered Mental status, SBP 90 or less, age 65 or older	Higher score means higher mortality. It does not select outpatients.
Oakland	LGIB: who can go home	Age, sex, prior LGIB admission, rectal exam findings, heart rate, systolic BP, hemoglobin	Score of 8 or less suggests safe discharge with outpatient work-up.

Risk scores support clinical judgment and do not replace it.

4. Resuscitation and transfusion

• Crystalloid for hypotension or ongoing bleeding while blood is arranged.
• Red cells at hemoglobin below 7 g/dL (consider 8 g/dL with cardiovascular disease). Massive bleeding or instability overrides the threshold; use a massive transfusion protocol.
• Platelets above 50 x 10^9/L in actively bleeding patients; correct coagulopathy selectively.
• Warfarin: do not delay endoscopy to normalize the INR. Reserve reversal (4-factor prothrombin complex concentrate preferred over plasma, plus vitamin K) for life-threatening bleeding.
• DOACs: hold. Specific reversal agents (idarucizumab for dabigatran; andexanet alfa where available, or 4-factor PCC, for factor Xa inhibitors) are for life-threatening bleeding only.
• Aspirin for secondary prevention: generally continue, or resume as soon as hemostasis is secure. Discuss dual antiplatelet therapy with cardiology before changing it.

5. Upper GI bleeding

Common causes

• Peptic ulcer disease (most common; NSAIDs, aspirin, H. pylori)
• Erosive esophagitis, gastritis, or duodenitis
• Esophageal or gastric varices, portal hypertensive gastropathy
• Mallory-Weiss tear
• Malignancy, angioectasia, GAVE (watermelon stomach), Cameron lesions, Dieulafoy lesion
• Less common but critical: aortoenteric fistula (prior aortic graft, “herald bleed”), hemobilia, hemosuccus pancreaticus

Before endoscopy

• Erythromycin 250 mg IV 30 to 120 minutes before endoscopy improves visualization (suggested unless QT prolongation is a concern).
• PPI: reasonable to start empirically, but it should never delay endoscopy.
• Timing: endoscopy within 24 hours of presentation, after resuscitation. Doing it within 12 hours in high-risk patients has not been shown to improve outcomes.
• Routine nasogastric lavage is not recommended.

Ulcer stigmata and endoscopic therapy (Forrest classification)

Forrest	Finding	Approx. rebleed risk without therapy	Endoscopic therapy?
Ia	Spurting	About 55%	Yes
Ib	Oozing	About 55%	Yes
IIa	Non-bleeding visible vessel	About 43%	Yes
IIb	Adherent clot	About 22%	Consider clot removal, then treat any underlying stigmata
IIc	Flat pigmented spot	About 10%	No
III	Clean base	About 5%	No; can be fed and discharged if otherwise low risk

• Modalities: bipolar or heater probe coagulation, hemoclips, or injection of absolute ethanol. Epinephrine injection alone is not enough; combine it with a second mechanical or thermal modality.
• Hemostatic powder (TC-325) is suggested for actively bleeding ulcers and is useful as a rescue or bridging option. Over-the-scope clips are suggested for recurrent ulcer bleeding after prior successful hemostasis.

After endoscopic therapy

• High-dose PPI (continuous or intermittent) for 3 days after successful hemostasis of a high-risk ulcer, then twice-daily oral PPI through day 14, then once daily.
• Test for H. pylori (biopsy, stool antigen, or breath test); treat if positive and confirm eradication. Testing can be falsely negative during acute bleeding or on a PPI, so repeat if the first test is negative.
• Stop NSAIDs. If an NSAID or aspirin is truly needed, use the lowest effective dose with a PPI.
• Rebleeding: repeat endoscopy first. If endoscopic therapy fails, use transcatheter arterial embolization (IR); surgery is reserved for when embolization fails or is not available.

Variceal bleeding (suspected cirrhosis)

• Vasoactive drug as soon as suspected: octreotide 50 mcg IV bolus, then 50 mcg per hour (or terlipressin), continued for 2 to 5 days.
• Antibiotic prophylaxis: ceftriaxone 1 g IV daily, up to 7 days. It lowers infection, rebleeding, and mortality.
• Restrictive transfusion to a hemoglobin of 7 to 8 g/dL. Over-transfusion raises portal pressure and rebleeding risk.
• Endoscopy within 12 hours. Esophageal varices: band ligation. Gastric varices (especially fundal): cyanoacrylate glue injection, with BRTO as an IR option.
• Pre-emptive TIPS within 72 hours (ideally within 24) for high-risk patients, such as Child-Pugh C (10 to 13 points) or Child-Pugh B with active bleeding at endoscopy.
• Refractory bleeding: balloon tamponade (Blakemore or Minnesota tube) or a covered esophageal stent as a bridge to TIPS. Secure the airway first.
• Secondary prophylaxis: non-selective beta-blocker plus repeat band ligation until varices are eradicated. Screen for hepatic encephalopathy and acute kidney injury during the admission.

6. Lower GI bleeding

Most acute LGIB stops on its own, so the aim is to find the group that will not.

Common causes

• Diverticular bleeding (the leading cause of major LGIB; painless, abrupt, often large volume)
• Hemorrhoids and other anorectal disease (fissure, rectal ulcer)
• Ischemic colitis (abdominal pain, then hematochezia, in a patient with hypotension or vascular disease)
• Colitis (IBD, infectious), post-polypectomy bleeding (up to about 14 days after the procedure), colorectal neoplasia
• Angioectasia, radiation proctopathy, Dieulafoy lesion, Meckel diverticulum (young patients)

Approach

1. Rule out an upper source if the patient is hemodynamically unstable or the BUN to creatinine ratio is high. Do an EGD before colonoscopy in that case.
2. Stable, low risk (for example Oakland 8 or less): outpatient work-up may be reasonable.
3. Unstable or ongoing hematochezia: resuscitate, then CT angiography as the first test. If a bleeding site is found, go to IR embolization or colonoscopy according to the source; if CT angiography is negative and bleeding continues, proceed to colonoscopy.
4. Admitted and stable: inpatient colonoscopy is recommended for most patients, but it can be non-emergent. Urgent colonoscopy within 24 hours has not been shown to reduce rebleeding or mortality. It may be unnecessary if bleeding has stopped and the patient had a high-quality colonoscopy within the past 12 months showing diverticulosis without neoplasia.
5. Preparation: split-dose polyethylene glycol (about 4 to 6 liters), by mouth or nasogastric tube, until the effluent is clear. Patients at risk of aspiration may need airway protection.

Localizing a bleed that is still active

Test	Detects bleeding at about	Notes
CT angiography	0.3 to 0.5 mL/min	Fast and widely available; first-line when unstable. Contrast risk is acceptable in life-threatening bleeding.
Tagged red cell scan	0.1 to 0.5 mL/min	Most sensitive; poor anatomic localization, so it rarely changes management.
Catheter angiography	0.5 to 1 mL/min	Therapeutic (embolization); ischemia is the main risk.

Treatment

• Diverticular bleeding with stigmata: through-the-scope clips or band ligation, with or without epinephrine.
• Post-polypectomy bleeding: clips, with or without epinephrine.
• Hemorrhoids: rubber band ligation. Angioectasia: argon plasma coagulation. Radiation proctopathy: argon plasma coagulation.
• Failed endoscopy: IR embolization. Surgery is a last resort, and segmental resection is only appropriate if the source is localized.
• Avoid NSAIDs after a diverticular bleed. Anticoagulation should usually be resumed once bleeding is controlled, because stopping it raises thromboembolism and mortality.

When both scopes are negative (obscure bleeding)

• Repeat the EGD or colonoscopy if the first was limited, then evaluate the small bowel.
• Video capsule endoscopy is the usual first test once overt bleeding has paused and no obstruction is suspected. Follow with device-assisted enteroscopy, CT or MR enterography as needed.
• Typical causes by age: young (Meckel diverticulum, Crohn disease, tumors); older (angioectasia, NSAID enteropathy, tumors). In suspected Meckel diverticulum, a technetium-99m pertechnetate scan is the test of choice.

7. Upper vs lower at a glance

	Upper GI bleed	Lower GI bleed
Discharge score	GBS 0 to 1	Oakland 8 or less
Transfusion threshold	Hb below 7 g/dL (8 if CVD; 7 to 8 in variceal)	Hb below 7 g/dL (consider 8 if CVD)
First test if unstable	Resuscitate, then EGD	Resuscitate, then CT angiography
Endoscopy timing	Within 24 hours	Non-emergent inpatient colonoscopy
Rescue when endoscopy fails	IR embolization, then surgery	IR embolization, then surgery
Pre-endoscopy extras	Erythromycin; octreotide and ceftriaxone if varices suspected	Bowel preparation

8. High-yield pearls

• About 50 to 100 mL of blood in the upper GI tract is needed to produce melena.
• Ulcers with a clean base or flat spot rarely rebleed, so they do not need endoscopic therapy.
• In active variceal bleeding, avoid large-volume crystalloid and avoid raising the hemoglobin above 8 g/dL.
• Consider aortoenteric fistula in any GI bleed with a prior aortic graft; endoscopy may not show the source and CT is required.
• In an unstable patient with LGIB, exclude an upper source before attributing the bleed to the colon.

References

• Laine L, et al. ACG Clinical Guideline: Upper Gastrointestinal and Ulcer Bleeding. Am J Gastroenterol. 2021;116(5):899-917.
• Sengupta N, et al. Management of Patients With Acute Lower Gastrointestinal Bleeding: An Updated ACG Guideline. Am J Gastroenterol. 2023.
• de Franchis R, et al. Baveno VII: Renewing consensus in portal hypertension. J Hepatol. 2022.
• HALT-IT Trial Collaborators. Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding. Lancet. 2020.

For educational purposes only. This note does not replace clinical judgment or local protocols.