The authors hypothesize that in patients with iron deficiency anemia or gastrointestinal bleeding, pan-intestinal capsule endoscopy is a safe and well tolerated procedure that may improve diagnostic yield comparatively to the current standard invasive colonoscopy.

Patients presenting with iron deficiency anemia (IDA) or overt GI bleeding are often submitted to conventional upper GI endoscopy and colonoscopy, followed by small bowel capsule endoscopy if diagnosis remains elusive. Recently, however, the possibility of performing pan-intestinal endoscopy using a video capsule that evaluates both the small bowel and the colon in a single non-invasive examination, opens new perspectives for the management of those conditions, particularly when the initial upper GI endoscopy has been non-diagnostic. The authors hypothesize that performing early pan-intestinal capsule endoscopy strategy may allow, in a safe and well tolerated manner, to identify which patients would benefit of further interventions, such as colonoscopy or invasive enteroscopy, guided by findings pre-identified at capsule examination. The study aims to evaluate whether pan-intestinal capsule endoscopy is superior to the current standard strategy of conventional colonoscopy after non-diagnostic upper endoscopy in patients with IDA or overt GI bleeding, regarding diagnostic yield, safety and tolerability.

Inclusion Criteria:

• Patients from external consultation, hospital ward or urgency department, with suspected GI bleeding presenting in the occult form as IDA (Hb <12.0 g/dL in female gender or <13.0 g/dL in male gender) and/or overt GI bleeding presenting as melaena and/or haematochezia, and with prior non-diagnostic upper GI endoscopy (esophagogastroduodenoscopy, EGD)

Exclusion Criteria:

1. Lack of informed consent
2. Suspected lesions at index EGD that could justify the anemia or digestive bleeding
3. Known history of gastroparesis or bowel dysmotility
4. Known or suspected intestinal stricture
5. Female patients with potential gynaecological source of bleeding causative of the clinical condition
6. Patients with severe malnutrition
7. Patients unable to walk at least for short periods and/or with neurological and/or psychiatric condition potentially favouring protocol deviations
8. Allergy or contra-indications to any of the drugs or products used in the study
9. Pregnancy or breastfeeding

The capsule endoscopy reader will be independent from the physicians performing the conventional colonoscopies, and all investigators will be blinded to each other's findings and reports. Capsule endoscopy and colonoscopy findings will be compared and in case of disagreement it will be discussed until a consensus is reached, if necessary, with the intervention of an independent third reader, experienced in both techniques and not involved in the primary reading of any of the examinations.