1	exp gastrointestinal hemorrhage/
2	(gastrointestinal adj2 (bleed* or hemorrhag* or haemorrhag*)).mp.
3	(Hematochezia* or hematemesis or haematemesis).mp.
4	exp hematemesis/
5	exp gastritis/
6	exp stomach ulcer/
7	(gastric and mucos* and lesion*).mp.
8	1 or 2 or 3 or 4 or 5 or 6 or 7
9	exp histamine H2 receptor antagonist/
10	(histamine and h2 and antagonist).mp.
11	(Burimamide or Cimetidine or ebrotidine or etintidine or Famotidine or lafutidine or loxtidine or Metiamide or mifentidine or Nizatidine or oxmetidine or Ranitidine or "roxatidine acetate" or tiotidine or zolantidine).mp.
12	9 or 10 or 11
13	exp proton pump inhibitor/
14	(proton adj pump adj inhibitor*).ti,ab,kw.
15	exp esomeprazole/
16	(Esomeprazole or Nexium or Esotrex or Alenia or Escz or Esofag or Nexiam).ti,ab,kw.
17	exp omeprazole/
18	(omeprazole or losec or nexium or prilosec or rapinex or zegerid or ocid or Lomac or Omepral or Omez).ti,ab,kw.
19	(pantoprazole or protium or protonix or Pantotab or Pantopan or Pantozol or Pantor or Pantoloc or Astropan or Controloc or Pantecta or Inipomp or Somac or Pantodac or Zurcal or Zentro).ti,ab,kw.
20	exp rabeprazole/
21	(rabeprazole or aciphex or dexrabeprazole or pariet or Zechin or Rabecid or Nzole‐D or Rabeloc).ti,ab,kw.
22	exp lansoprazole/
23	(lansoprazole or lanzoprazole or agopton or bamalite or Inhibitol or Levant or Lupizole or lanzor or monolitum or ogast or ogastro or opiren or prevacid or prezal or promeco or takepron or ulpax or zoton).ti,ab,kw.
24	exp dexlansoprazole/
25	(Dexlansoprazole or Kapidex or Dexilant).ti,ab,kw.
26	(tenatoprazole or benatoprazole).ti,ab,kw.
27	13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26
28	exp sucralfate/
29	(sucralfate or sulfate or antepsin or carafate or ulcerban or ulcogant or ulsanic).mp.
30	28 or 29
31	(protect* and (agent* or drug or medicine or medication)).mp.
32	(gastro* adj2 mucosa*).mp.
33	gastric mucosa*.mp.
34	stomach mucosa*.mp.
35	32 or 33 or 34
36	31 and 35
37	12 or 27 or 30 or 36
38	(infan* or newborn or neonat* or premature or very low birth weight or low birth weight or VLBW or LBW).mp.
39	exp infant/
40	38 or 39
41	(human not animal).mp.
42	(randomized controlled trial or controlled clinical trial or randomized or placebo or clinical trials as topic or randomly or trial or clinical trial).mp.
43	40 and 41 and 42
44	8 and 37 and 43
45	from 44 keep 1‐123