Scientists Find Neurons in The Gut That Could Be Driving Constipation And Pain - ScienceAlert

What the report says

ScienceAlert reported on July 28, 2026, that a new mouse study has identified a subset of nerve cells in the gut that may be linked to both colon movement and sensations of pain or discomfort. The work focuses on neurons associated with Pdyn, the gene for prodynorphin, within the enteric nervous system — the gut’s extensive nerve network sometimes called a “second brain.”

According to ScienceAlert, researchers used genetically modified mice to locate and stimulate these neurons. In isolated mouse colons, activating the cells with light made fecal pellets more likely to move forward, suggesting a role in propelling material through the bowel without input from the brain or spinal cord. In living mice, however, stimulation did not increase stool output, which physician-scientist Daniel Verbaro of Washington University School of Medicine in St. Louis said may reflect the combined influence of gut nerves and external nerve signals in an intact animal.

The same stimulation in live mice produced freezing and eye-tightening behaviors, which are commonly interpreted in mice as signs of pain or discomfort. The researchers also found features suggesting the neurons might detect inflammation-related signals, but ScienceAlert noted this has not yet been directly shown. Similar enteric neurons have been observed in humans, though their function in people remains unknown.

The study is available as a bioRxiv preprint and has not yet been peer reviewed. ScienceAlert framed the findings as potentially relevant to future understanding of chronic constipation, abdominal pain and irritable bowel syndrome, while emphasizing that those conditions were not directly tested and that further research is needed.