The Effects of TTNS, TTNS Combined With PHUS, and Conventional Therapy With PHUS in the Treatment of PFC.

Overview

This study is a randomized, controlled trial designed to evaluate the effects of transcutaneous tibial nerve stimulation (TTNS), TTNS combined with pocket-sized handheld ultrasound (PHUS), and conventional therapy with PHUS on children with functional constipation (FC). Participants will be stratified into three intervention arms (n=20 per group). FC will be defined based on the Rome IV diagnostic criteria, in the absence of organic or anatomical causes. Participants will be between 4 and 14 years old and will have experienced failure of conservative treatment for at least three months prior to enrollment. The primary outcomes include changes in rectal ultrasound parameters and symptom severity scores. Ultrasound assessments will be conducted by trained clinicians using standardized protocols. Monitoring for adverse events will be performed throughout the intervention phase. Safety considerations include predefined exclusion criteria, such as underlying neurological, metabolic, or cardiac conditions.

Eligibility Criteria Inclusion Criteria: Children aged 4 to 14 years. Diagnosis of functional constipation (FC) established prior to study enrollment. FC is defined according to the Rome IV diagnostic criteria, in the absence of identifiable organic or anatomical causes (e.g., no endocrine, metabolic, anatomical, or neuromuscular dysfunction). No additional diagnostic testing is required for inclusion. Ability to complete daily diaries and TTNS sessions, either independently or with caregiver support. Documented failure of conservative medical treatment following at least three months of therapy. Exclusion Criteria: Malformations of the digestive system or rectal anatomical anomalies (e.g., large intestinal atresia or stenosis, Hirschsprung's disease, congenital anorectal malformations). Neurological or psychiatric conditions (e.g., cerebral palsy, spina bifida, intellectual disability, anorexia nervosa). Major cognitive impairments. Metabolic disorders (e.g., diabetes mellitus, diabetes insipidus, scurvy, phenylketonuria). Endocrine disorders (e.g., hypothyroidism). Cardiovascular conditions such as heart disease or arrhythmias, or presence of ventriculoperitoneal shunts or cardiac pacemakers, due to potential electrical interference. History of thoracic or abdominal surgery. Presence of dermatological lesions in the area of electrode application. Presence of active electronic implants.