Scientists have developed a smart pill that scans the patient for signs of gastrointestinal cancer from the inside as it travels through the digestive tract. 

The pill is designed to replace conventional endoscopies and colonoscopies with a simpler, less invasive alternative. This approach could enable earlier cancer diagnoses, allowing doctors to intervene when the cancer is still curable and more likely to respond to treatment. 

“Gastrointestinal cancer presents a considerable threat to human health, accounting for roughly one-quarter of the global cancer incidence and up to one-third of cancer-related deaths,” writes Daxiang Cui, Chair Professor of Shanghai Jiao Tong University. “Early and precise diagnosis is crucial for improving survival outcomes and prognosis.”

By bringing advanced imaging technology inside the body, this approach could mark a shift in how doctors examine the digestive tract while making cancer screening more accessible, convenient, and patient-friendly. 

Shining a light from within

Traditionally, gastrointestinal cancer is diagnosed through endoscopy—a procedure in which a long, flexible tube with a small camera at its tip is inserted either through the mouth or the colon to examine the digestive tract for signs of cancer. While endoscopy is considered a quick and effective diagnostic tool, patients often find it unpleasant or uncomfortable. In some cases, sedation is required, and, although rare, the procedure carries a risk of complications including injuring the digestive tract during the examination. 

In recent years, conventional endoscopies have increasingly been complemented or replaced by capsule endoscopy. Instead of using a tube, this approach relies on a pill-sized capsule that is swallowed and captures video images as it travels through the digestive tract. Different capsule devices are currently available to examine specific regions of the digestive  tract. 

However, commercial capsules in use today take images using white light, which can only scan surfaces and can therefore miss small lesions or tumors located beneath the surface of the tissue. In addition, wireless data transmission from inside the body can compromise the image resolution, increasing the risk of early-stage cancers going undetected when treatment is most effective.

To address these limitations, Cui’s team developed a smart capsule with two complementary imaging modes. One uses conventional white light to navigate the digestive tract and determine the smart pill’s position, while the other employs near-infrared light that can penetrate deeper into the surrounding tissue while maintaining high image resolution and sensitivity. 

The near-infrared mode is designed to work in combination with a fluorescent contrast agent—similar to how a contrast dye is used during a CT scan to highlight areas that would otherwise be difficult to see. As the capsule passes through the digestive tract, it detects the fluorescent signal and creates detailed images that help doctors identify tumor lesions. The smart pill is powered wirelessly and guided using external magnetic fields, allowing researchers to precisely control its movement from outside the body during the examination. 

In experiments using pig stomachs, the smart pill successfully detected lesions as small as 100 micrometres, as well as tumors located up to 4 mm deep within the tissue. The device was then tested in live mice, where the capsule was able to accurately locate tumor lesions within the digestive tract.

“The system provides a high-quality, non-invasive imaging solution for the early screening of gastrointestinal cancers, and it is anticipated to play a vital role in clinical diagnostics,” says Cui.

While the technology will require further testing before it can routinely replace endoscopies, this study points to a future in which medical imaging devices increasingly become smaller, intelligent, and less invasive. One day, getting a comprehensive cancer screening could be as simple as swallowing a pill. 

Reference: Weicheng Wang et al., Wireless, Deep-Seeing Smart Pill: A NIR-II Fluorescence Imaging Capsule Endoscope for Gastrointestinal Cancer, Advanced Science (2026). DOI: 10.1002/advs.75532

Featured Image Credit: Julien Tromeur via Pixabay