Background and Rationale Chronic functional constipation (FC) is a highly prevalent disorder that significantly diminishes quality of life and is frequently associated with psychological comorbidities such as anxiety and depression. Within the framework of Traditional Chinese Medicine (TCM), a prominent subtype is "Yang deficiency type" FC. Its pathophysiology is understood as a deficiency of Yang Qi, resulting in slowed metabolism and weakened motility of the large intestine. The acupoints Tianshu (ST25), the Front-Mu point of the Large Intestine, and Guanyuan (CV4), the Front-Mu point of the Small Intestine and a crucial point for nourishing Yuan Qi, are classically combined to warm Yang and regulate intestinal function. This trial investigates whether the combined thermal and stimulatory effects of warm needling at these points offer superior and more sustained clinical benefits compared to electroacupuncture alone.
Study Design and Methodology This is a single-center, parallel-group, superiority randomized controlled trial with a 1:1 allocation ratio, conducted at the First Affiliated Hospital of Henan University of Chinese Medicine. A total of 60 participants diagnosed with Yang deficiency type chronic FC will be randomized into either an experimental group (warm needling) or a control group (electroacupuncture).
Intervention Details Experimental Group (Warm Needling): After standard disinfection, single-use sterile stainless steel needles (0.25×40mm) will be inserted perpendicularly at Tianshu (ST25) and Guanyuan (CV4) to achieve deqi (the characteristic needling sensation). Subsequently, a prepared moxa stick (approx. 2cm in diameter, 3cm in length) will be attached to the handle of each needle and ignited. The heat is conducted down the needle to the deeper tissues. Needles will be retained for 30 minutes with careful monitoring to prevent burns.
Control Group (Electroacupuncture): Needle insertion and deqi technique will be identical to the experimental group. Needle handles will then be connected to an electroacupuncture device (Hwato SDZ-V series) delivering a dense-sparse wave (2/15 Hz) at an intensity sufficient to produce mild, non-painful muscle twitching. Needles will be retained for 30 minutes.
Both groups will receive treatment every other day, three times weekly, for a total course of four weeks.
Therapeutic Rationale Tianshu (ST25) is strategically selected for its direct regulatory effect on large intestine function. Guanyuan (CV4) is chosen for its powerful action in warming and tonifying Yang Qi. The warm needling technique synergistically combines the meridian-regulating effect of acupuncture with the deep, penetrating warmth of moxibustion. This is hypothesized to enhance local circulation, modulate neuroendocrine pathways involved in the brain-gut axis, and provide a more potent Yang-tonifying effect than electroacupuncture alone, potentially leading to more durable improvements in bowel function.
Follow-up and Outcome Assessment To evaluate the sustainability of the treatment effect, all participants will undergo a follow-up assessment six months after the completion of the 4-week treatment course. No study-related interventions will be provided during this period. The primary outcome is the change from baseline in the Constipation Severity Score (CSS) at week 4 and month 6. Secondary outcomes include changes in TCM syndrome score, Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS), and Patient Assessment of Constipation Quality of Life (PAC-QOL) scale. Outcome assessors and statisticians will be blinded to group allocation. Analysis will be conducted on an intention-to-treat basis.
Significance This study aims to provide rigorous clinical evidence on the efficacy of warm needling for a well-defined TCM condition. By including a 6-month follow-up, it will offer valuable insights into the durability of the therapeutic response, informing clinical practice and guiding future research on non-pharmacological interventions for chronic functional constipation.
