Slow-transit constipation, a subtype of chronic constipation caused by colonic dysmotility, affects an estimated 2-4% of people worldwide (about 6.7-13.4 million in the US), and common treatments such as laxatives do not address the underlying dysmotility. Clinicians treating colonic dysmotility using dry needling electrical stimulation (DNES) need a method to standardize needle placement and objectively evaluate colonic muscle activity to improve treatment outcomes for individuals struggling with colonic dysmotility.