GI Endoscopy · 7 min read
Reading a Bleeding Capsule: Saurin P0-P2, and Why Lewis Is a Crohn's Score
This URL is a bleeding-read page. Lewis belongs to Crohn's mucosal activity. The leftover stub had those backwards.
Saurin 2003 (PMID 12822092) is how you grade bleeding potential: P0 none, P1 uncertain (red spot, small erosion), P2 high (angioectasia, large ulcer, tumor, varix). P2 is what should move the needle toward device-assisted enteroscopy. The Lewis score (Gralnek, PMID 17956598) is a different tool: villous edema, ulcer, stenosis, tertiles, cutoffs 135 and 790. It measures inflammatory change, usually Crohn's. Putting a Lewis number on an angioectasia study is theater.
Experienced teaching points
Clinical Pearls
- P2: treat or plan DAE. P1: describe it, do not over-call it as the source. P0: say so.
- Fresh blood without a lesion still localizes. Report the first frame of blood and the last.
- Lewis <135 insignificant, 135-790 mild, 790 or more moderate to severe. Crohn's language, not bleeding language.
- Who should swallow a capsule: indications page. Who should not: retention page.
Clinical Bottom Line
| Score | What it is for |
|---|---|
| Saurin P0 | No bleeding potential. Veins, diverticula without blood, nodules. Do not send DAE for these. |
| Saurin P1 | Uncertain: red spots, small erosions. Report them. They are not a mandate to enteroscope. |
| Saurin P2 | High potential: angioectasia, large ulcer, tumor, varix. This is the finding that should change the plan. |
| Lewis <135 / 135-790 / ≥790 | Inflammatory change, usually Crohn's. Not a bleeding grade. Cotter 2015 (PMID 25412092) validated the cutoffs. |
How do I read a study done for blood?
Saurin compared capsule with push enteroscopy in 58 completed patients with obscure bleeding. Capsule found more clinically relevant lesions. The useful leftover is the P classification, not the 2003 camera. Write P0, P1, or P2 in the impression. Write the small-bowel time of the first P2. That time is how the enteroscopist chooses mouth versus anus.
Active blood without a lesion is still a localization. Note the first and last frames with blood. A completely negative, complete-to-cecum study in a quiet patient can be watched (ESGE 2022). An incomplete study is not a negative study.
When do I use Lewis?
When the question is small-bowel inflammatory activity, usually Crohn's after a negative ileocolonoscopy, or follow-up of known small-bowel Crohn's. Gralnek 2008 built the index from villous edema, ulcer, and stenosis across tertiles defined by transit time. Less than 135: normal or clinically insignificant. 135 to 790: mild. 790 or more: moderate to severe. Cotter showed readers can agree on those bins.
Lewis does not diagnose Crohn's by itself. NSAID enteropathy, infection, and ischemia make ulcers too. Do not tell a bleeding patient their Lewis score is 900 because the software printed it. Indications: capsule page.
Selected references
- Saurin JC, et al. Diagnostic value of endoscopic capsule in patients with obscure digestive bleeding. Endoscopy. 2003;35:576-584.
- Gralnek IM, et al. Development of a capsule endoscopy scoring index for small bowel mucosal inflammatory change. Aliment Pharmacol Ther. 2008;27:146-154.
- Cotter J, et al. Validation of the Lewis score for the evaluation of small-bowel Crohn's disease activity. Endoscopy. 2015;47:330-335.
- Pennazio M, et al. ESGE Guideline Update 2022. Endoscopy. 2023;55:58-95.
Last reviewed September 20, 2026. Written for clinicians reading a capsule done for blood or iron deficiency, and for the ones who were taught to drop a Lewis number on every study.
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