Blood Detection Capsule May Help in Upper GI Bleeding

SAN DIEGO — A real-time, blood-sensing capsule (PillSense) is a safe and effective diagnostic tool for patients with suspected upper gastrointestinal (GI) bleeding that can aid patient triage, reduce unnecessary procedures, and optimize resource use, a study found.

Notably, patients with negative capsule results had shorter hospital stays and lower acuity markers, and in more than one third of cases, an esophagogastroduodenoscopy (EGD) was avoided altogether without any observed adverse events or readmissions, the study team found.

“Our study shows that this novel capsule that detects blood in the upper GI tract (PillSense) was highly sensitive and specific (> 90%) for detecting recent or active upper GI blood, influenced clinical management in 80% of cases and allowed about one third of patients to be safely discharged from the emergency department, with close outpatient follow-up,” Linda Lee, MD, medical director of endoscopy, Brigham and Women’s Hospital and associate professor of medicine, Harvard Medical School, Boston, told Medscape Medical News.

The study was presented at Digestive Disease Week (DDW) 2025.

Real-World Insights

EGD is the gold standard for diagnosing suspected upper GI bleeding, but limited access to timely EGD complicates diagnosis and resource allocation.

Approved by the US Food and Drug Administration, PillSense (EnteraSense) is an ingestible capsule with a reusable receiver that provides a rapid, noninvasive method for detecting upper GI bleeding. The capsule analyzes light absorption to identify blood and transmits the result within 10 minutes.

Lee and colleagues evaluated the real-world impact of this point-of-care device on clinical triage and resource allocation, while assessing its safety profile.

They analyzed data on 43 patients (mean age 60 years; 72% men) with clinical suspicion of upper GI bleeding in whom the device was used. The most common symptoms were symptomatic anemia (70%), melena (67%), and hematemesis (33%).

Sixteen PillSense studies (37%) were positive for blood detection, and 27 (63%) were negative.

Compared to patients with a positive capsule results, those without blood detected by the capsule had shorter hospital stays (mean, 3.8 vs 13.4 days, P = .02), lower GBS scores (mean, 7.93 vs 12.81; P = .005), and fewer units of blood transfused (mean, 1.19 vs 10.94; P = .01) and were less apt to be hemodynamically unstable (5 vs 8 patients; P = .03).

Capsule results influenced clinical management in 80% of cases, leading to avoidance of EGD in 37% and prioritization of urgent EGD in 18% (all had active bleeding on EGD).

Capsule use improved resource allocation in 51% of cases. This included 12 patients who were discharged from the ED, six who were assigned an inpatient bed early, and four who underwent expedited colonoscopy as upper GI bleeding was ruled out, they noted.

Among the eight patients who did not undergo EGD, there were no readmissions within 30 days and no adverse events. There were no capsule-related adverse events.

“Clinicians should consider using this novel capsule PillSense as another data point in the management of suspected upper GI bleed,” Lee told Medscape Medical News.

“This could include in helping to triage patients for safe discharge from the ED or to more urgent endoscopy, to differentiate between upper vs lower GI bleed and to manage ICU patients with possible rebleeding,” Lee said.

Important Real-World Evidence

Reached for comment, Shahin Ayazi, MD, esophageal surgeon, Director, Allegheny Health Network Chevalier Jackson Esophageal Research Center, Pittsburgh, Pennsylvania, said this study is important for several reasons.

“Prior investigations have established that PillSense possesses a high negative predictive value for detecting upper GI bleeding and have speculated on its utility in triage, decision-making, and potentially avoiding unnecessary endoscopy. This study is important because it substantiates that speculation with clinical data,” Ayazi, who wasn’t involved in the study, told Medscape Medical News.

“These findings support the capsule’s practical application in patient stratification and clinical workflow, particularly when diagnostic uncertainty is high and endoscopic resources are limited,” Ayazi noted.

In his experience, PillSense is “highly useful as a triage adjunct in the evaluation of suspected upper GI bleeding. It provides direct and objective evidence as to whether blood is currently present in the stomach,” he said.

“In patients whose presentation is ambiguous or whose clinical scores fall into an intermediate risk zone, this binary result can provide clarity that subjective assessment alone may not achieve. This is particularly relevant in settings where the goal is to perform endoscopy within 24 hours, but the volume of consults exceeds procedural capacity,” Ayazi explained.

“In such scenarios, PillSense enables physicians to stratify patients based on objective evidence of active bleeding, helping to prioritize those who require urgent endoscopy and defer or even avoid endoscopic evaluation in those who do not. The result is a more efficient allocation of endoscopic resources without compromising patient safety,” he added.

Ayazi cautioned that the PillSense capsule should not be used as a replacement for clinical evaluation or established risk stratification protocols.

“It is intended for hemodynamically stable patients and has not been validated in cases of active or massive bleeding. Its diagnostic yield depends on the presence of blood in the stomach at the time of capsule transit; intermittent or proximal bleeding that has ceased may not be detected, introducing the potential for false-negative results,” Ayazi told Medscape Medical News.

“However, in prior studies, the negative predictive value was high, and in the present study, no adverse outcomes were observed in patients who did not undergo endoscopy following a negative PillSense result,” Ayazi noted.

“It must also be understood that PillSense does not localize the source of bleeding or replace endoscopy in patients with a high likelihood of active hemorrhage. It is not designed to detect bleeding from the lower GI tract or distal small bowel. Rather, it serves as an adjunct that can provide immediate clarity when the need for endoscopy is uncertain, and should be interpreted within the broader context of clinical findings, laboratory data, and established risk stratification tools,” he added.

The study had no specific funding. Lee and Ayazi had no relevant disclosures.