This is a prospective, non-randomized, open-label clinical investigation to evaluate feasibility, effectiveness and safety of the PillSense System, the transit of the PillSense Capsule through the GI tract, patient tolerability of the PillSense Capsule, and blood detection.

Patient eligibility as set out in the inclusion/exclusion criteria for the clinical investigation will be reviewed prior to study enrollment. Prior to administering the PillSense Capsule, the PillSense Receiver will be paired with the PillSense Capsule. The PillSense Receiver collects and displays real-time information gathered by the PillSense Capsule. The PillSense Receiver interprets the data and displays a result message "Blood detected" or "No Blood detected". The overall investigation from the PillSense Capsule activation and ingestion until the result message is displayed takes less than 10 minutes. Esophagogastroduodenoscopy (EGD) should be completed immediately or up to 4 hours after PillSense Capsule administration in each patient that receives a "Blood detected" or "No blood detected" result to confirm the result achieved with the PillSense System. The endoscopy will be conducted according to the site's standard of care. Prior to discharge each patient will undergo an X-Ray examination to evaluate for PillSense Capsule presence. Following discharge, if there is no verifiable evidence that the PillSense Capsule passed through the gastrointestinal tract (GIT) (such as a photograph of stool with capsule in it or photograph of the capsule alone), the patient may undergo an X-Ray examination at Day 7 ± 5 days and, if necessary, at Day 14± 7 days to ascertain the passage status of the PillSense Capsule. If the PillSense Capsule did not pass through the GIT, it should be removed by an endoscopic method.

Inclusion Criteria

• Age >=18 years
• Ability to provide informed consent
• Clinical suspicion of UGIB

Exclusion Criteria:

• Circulatory or hemodynamic instability
• Known GI tract stricture
• Using an implantable electrical device
• Difficulties in swallowing pills the size of the capsule
• History of: achalasia or known esophageal dysmotility; gastroparesis; severe constipation; Crohn's disease; bowel obstruction
• Currently taking medications intended for stimulation of GI motility
• Currently pregnant or breastfeeding, or intend to become pregnant during the investigation
• Suspected or previously diagnosed obstructing gastrointestinal tumor

Safety Population

From Time of PillSense Administration through Follow-up Visit 3 (Up to 21 days).

Treatment emergent adverse events defined as an adverse event that began or worsened during or after PillSense Capsule administration.