Pan-intestinal Capsule Endoscopy Versus Colonoscopy in Iron Deficiency Anemia or Overt GI Bleeding

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.

• Pan-intestinal capsule endoscopy (Diagnostic test), also known as Conventional colonoscopy: Patients with iron deficiency anemia or overt GI bleeding with non-diagnostic upper GI endoscopy will be submitted to same-day pan-intestinal capsule endoscopy using PillCam Crohn's Capsule (Medtronic) followed by conventional colonoscopy under propofol sedation

Primary outcomes

• Number of participants with at least one potentially bleeding lesion detected in small bowel and/or colon [2 weeks]: Potentially bleeding lesions include tumors, angiectasias, erosions, ulcers, diverticula or active bleeding

Secondary outcomes

• Safety: number of participants with any procedure-related adverse events [2 weeks]: Adverse events include capsule retention, bowel preparation-related (nausea, vomiting, dizziness, seizures, abdominal pain or bloating), bleeding, perforation or cardiopulmonary complications
• Patient's preference: number of participants preferring capsule endoscopy or colonoscopy [2 weeks]: Questionnaire regarding preference based on overall experience and perception of the strengths and limitations of each procedure

Other outcomes

• Quality of bowel preparation at capsule endoscopy (small bowel) [2 weeks]: Use of validated Brotz scale (4-grade qualitative assessment as excellent, good, fair or poor bowel preparation)
• Quality of bowel preparation at capsule endoscopy (colon) [2 weeks]: Use of validated scale CC-CLEAR (Colon Capsule CLEansing Assessment and Report) - quantitative scale: adequate bowel preparation if overall score >= 6 points, and >= 2 points in each bowel segment (right, transverse, and left colon). Overall 0-5 points inadequate; 6-7 points good; 8-9 points excellent bowel preparation
• Quality of bowel preparation at colonoscopy [2 weeks]: Use of validated Boston Bowel Preparation Scale: quantitative scale 0-9 points - adequate bowel preparation if overall score >= 6 points, and >= 2 points in each bowel segment (right, transverse, and left colon)

Sex: All, ages: 8 Years to 100 Years

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

• Results publication: Souto M, Goncalves J, Silva VM, Rosa B, Cotter J. Concordance Between Pan-Intestinal Capsule Endoscopy and Colonoscopy for the Detection and Characterization of Colonic Lesions: Post Hoc Analysis on the Impact of Colonic Transit Time. J Gastroenterol Hepatol. 2026 Aug;41(8):2419-2426. doi: 10.1111/jgh.70505. Epub 2026 Jun 21. PMID 42323957

• Bruno Rosa, MD, Principal investigator, Gastroenterology Department, Hospital da Senhora da Oliveira - Guimarães, Portugal