Forrest Classification of Upper GI Bleeding

1. What Was Published in 1974, and What Was Added Afterwards

James Forrest, Niall Finlayson and David Shearman published Endoscopy in gastrointestinal bleeding in the Lancet in August 1974. It is indexed as a comparative study of endoscopy against barium radiology, not as a proposal for a grading scheme, and the six-class lettering used every day, Ia through III, is not the lettering in that paper. It accumulated afterwards, in the hands of the people who needed to say which ulcers to inject.

This tool does not tell you what the 1974 paper printed, because the 1974 paper was not read for it: only its citation record was. Every therapeutic recommendation attached to a class here is attributed to the European or American guideline that prints it, both of which use the modern lettering explicitly and were read at source.

2. Wash First, Then Decide What You Are Looking At

The American guideline does not write "adherent clot". It writes "adherent clot resistant to vigorous irrigation", and the qualifier is doing the work. Studies that irrigated properly found most clots come away. What is underneath is very often a clean base or a flat spot, which needs nothing, and occasionally a visible vessel or a spurting artery, which needs everything. So the sequence is wash, classify, treat.

• Classify before washing and you carry the risk in both directions. A Forrest III called a IIb costs the patient three days of intravenous acid suppression and a bed. A Ia called a IIb is a vessel nobody treated.
• The non-bleeding visible vessel is not a vessel you can see. It is a raised, pigmented protuberance on the ulcer floor, in most cases a plug of clot sealing a breach in an artery running under the ulcer base, sometimes called a sentinel clot. That is why it is treated although nothing is bleeding while you look at it.
• It must be raised. A flat pigmented spot is a different class with a different plan, and the distinction is elevation, not colour.
• Washing will not remove it, and if washing does remove it, it was a clot and not a vessel.

3. Adrenaline Alone Is Not Treatment

Injected adrenaline works by volume tamponade and vasoconstriction, and both wear off. It buys a clear field and the time to place a second modality accurately, but on its own it leaves the artery as it was.

• 2021 European guideline: "epinephrine injection plus a second hemostasis modality" for an actively bleeding ulcer.
• 2026 update: thermal therapy, mechanical therapy or a sclerosant "each as monotherapy or in combination with epinephrine injection", which permits those three alone and never permits adrenaline alone.
• The dose. No guideline read for this tool doses it. The 30 mL of 1:10,000 printed here comes from a randomised trial of 228 patients. Twenty millilitres left a rebleeding rate of 20.3 per cent, against 5.3 per cent at 30 mL. Forty millilitres bought a further 2.5 percentage points, at the price of a significantly higher perforation rate.

4. The Class Is Less Reproducible Than It Looks

Forty-seven experienced endoscopists in Piedmont classified the same 25 videotaped examinations. Agreement beyond chance was good where blood was moving and poor where it was not.

The authors opened by pointing out that the wide range of published rebleeding rates for the same stigma is itself evidence that the definitions are not applied uniformly. That is the honest frame for every percentage in this tool, including the ones it prints.

5. What the Class Predicts, and What It Does Not

A prospective registry of 397 patients with bleeding peptic ulcers, followed for 30 days, gives the most quotable modern figures. Rebleeding occurred in 74 of the 397, 18.6 per cent overall, and was highest in Forrest Ia at 59 per cent.

• The odds of rebleeding among Ib, IIa, IIb and IIc were similar to one another. The middle of the scale is not a graded slope; it is a plateau.
• Prediction was more reliable for gastric ulcers than for duodenal ones.
• The classification did not predict mortality at all. A patient with a clean base can still die of the illness that put the ulcer there, and this tool prints no mortality figure by class for that reason.
• The authors proposed collapsing the scheme to three bands, high risk Ia alone, increased risk Ib through IIc, low risk III. It has not been adopted, and both current guidelines still write the six classes.

6. Three Documents, Three Answers on Haemostatic Powder

This is the clearest example of why a tool should print positions rather than a verdict.

The three are not as far apart as they look once "sole treatment" and "monotherapy" are read as the same idea. Powder stops a field you cannot otherwise see or reach, so that something durable can follow. Where the units differ is on whether a case ends there.

7. Seventy-Two Hours of Acid, and Why the Drip Is Optional

Clot stability depends on gastric pH. Pepsin digests a clot below about pH 6 and platelet aggregation fails below about pH 5.4, so profound and continuous acid suppression is not adjuvant treatment here: it is what keeps the endoscopic result in place while the vessel organises. Seventy-two hours is the window in which almost all rebleeding happens.

• Bolus plus infusion: 80 mg followed by 8 mg per hour, the regimen the European guideline names, and the regimen a district hospital cannot always staff.
• Intermittent dosing: a meta-analysis of randomised trials in endoscopically treated high-risk ulcers found it non-inferior, with a risk ratio for seven-day rebleeding of 0.72 and an absolute difference of minus 2.64 per cent, comfortably inside the pre-specified margin. Both the 2021 guidelines now permit either. Where the ward cannot run a syringe pump reliably for three days, it is a defensible choice and not a compromise.

8. A Negative Rapid Urease Test in a Bleeding Stomach Means Very Little

Blood in the stomach, and the proton pump inhibitor already running, both suppress the organism and the test. A meta-analysis pooled every method in this specific setting.

Hence the European recommendation to retest anyone negative at the index endoscopy. In a series of patients whose in-hospital breath test was negative, 15 of 18 turned positive when repeated after stopping the acid suppression, and the only factor associated with the false negative was how long after admission the test was done. Eradication is what stops this ulcer bleeding again, so a missed diagnosis here is a readmission later.

9. What Changed in 2026

The European guideline was updated in May 2026 with 19 new or revised statements. Five of them change what happens to a Forrest class.

A correction to that update appeared in the same journal in May 2026. It was not read for this tool, so what it corrects is not known here, and this page cannot tell you whether any statement above is among the corrected ones. Read it first.

10. The Indian Picture, and What Has Not Been Studied Here

A search of the published literature on 3 September 2026 found no Indian cohort reporting outcomes by Forrest class. Two things have not been published: the distribution of classes in Indian endoscopy units, and the rebleeding rate for each class in Indian hands. So every per-class percentage in this tool is European, from patients on average a generation older than the Indian patient with a bleeding ulcer.

What Indian data there is describes the illness rather than the class. A prospective series of 138 adults at a teaching hospital in Dehradun found:

• Peptic ulcer disease the commonest source at 56.5 per cent, ahead of variceal bleeding at 25.4 per cent.
• Most patients between 31 and 50 years old.
• Alcohol use in 43.5 per cent, NSAID exposure in 36.2 per cent.
• Haemoglobin below 7 g/dL in 29 per cent, and 63.8 per cent transfused.
• Endoscopic haemostasis successful in 87 per cent, 13 per cent rebled, 9.4 per cent died.

Three things follow for practice here. NSAID exposure is often bought rather than prescribed and will not appear in a drug history unless it is asked for by name. The younger age of the Indian patient makes an elective operation for a failed endoscopic result a different proposition from the same operation in a European series. And a unit with neither an over-the-scope clip nor an interventional radiology service on site is following a guideline whose escalation ladder assumes both, which is a reason to have the surgical conversation early rather than a reason to ignore the ladder.