Upper gastrointestinal bleeding (UGIB) is a common and potentially lethal medical emergency, which requires hospitalization and healthcare resources. Despite the changing epidemiology and advancement of endoscopic therapy in the recent decade, the all-cause mortality of UGIB remains high (>2%). An accurate risk stratification is necessary to triage patients into low- or high-risk groups, in order to inform clinicians for the necessity and timing of urgent endoscopy. However, existing pre-endoscopy risk scores, such as the Glasgow-Blatchford score (GBS), Rockall score and AIMS65 score, are suboptimal in predicting relevant clinical outcomes. An alternative strategy for risk stratification is urgently warranted in patients with UGIB to guide the next step of management.

In a pre-clinical study, the sensitivity and specificity of HemoPill® prototype were 95% and 87.5% respectively, when the sensors were positioned close to the bleeding point. Furthermore, several human clinical studies have proven the feasibility and accuracy of HemoPill® in healthy volunteers and patients with suspected UGIB. Capsule ingestion was well tolerated with no device-related adverse event or capsule retention. All patients with negative HI were found to have no active endoscopic bleeding (true negative, 100%, 17/17). In patients with bleeding >20ml, true positive HI signals were detected (100%, 2/2) In a retrospective multi-center study, 61 patients with suspected UGIB were recruited to use HemoPill®. Among the capsule-positive cases, subsequent endoscopy confirmed active bleeding in 57% (20/35) of them. None of the capsule-negative patients rebled (0%, 0/25), which prevented unnecessary emergent endoscopy in 72% of them (18/25).

From December 2023 to February 2024, the investigator conducted a pilot study and screened 51 adult subjects with symptoms and signs of suspected UGIB in Prince of Wales Hospital. Among them, the investigator recruited 20 eligible subjects to receive HemoPill® examination before oesophago-gastro-duodenoscopy (OGD). The overall sensitivity was 80% with a negative predictive value of 87.5%. The area-under-receiver-operating-characteristic curve was 0.633.

The pilot data demonstrated a huge potential for this novel, non-invasive, easy-to-use device as UGIB screening in the real-world. A large-scale, prospective validation study will be conducted to evaluate the diagnostic performance of the new generation HemoPill® acute capsule in UGIB.

Inclusion Criteria:

1. Participants have symptoms and signs of suspected UGIB (melena, per rectal bleeding, coffee ground vomiting, prior hematemesis);
2. Participants will undergo urgent or elective OGD within 24 hours from recruitment;
3. Written consent obtained.

Exclusion Criteria:

1. Contraindications for OGD (e.g. respiratory failure, suspected perforation);
2. Contraindications for capsule endoscopy (e.g. known gastrointestinal obstruction or stricture, severe dysphagia, impaired consciousness);
3. Cardiac pacemaker or implanted electromedical devices;
4. History of gastrectomy or bowel resection;
5. Ongoing fresh hematemesis requiring emergent endoscopy;
6. Unstable hemodynamics despite adequate resuscitation requiring emergent endoscopy (i.e. systolic blood pressure <100mmHg or pulse rate >100 per minute);
7. Advanced comorbidities (defined as American Society of Anesthesiologists grade 4 or above);
8. Pregnancy.

Endoscopists will be blinded from the Hemopill capsule examination results.