**Background:** Functional constipation (FC) is a common functional gastrointestinal disorder in children, accounting for up to 25% of visits to pediatric gastroenterologists and 3% of general pediatric outpatient visits globally. The condition significantly impacts quality of life and psychological health of both children and families. This narrative review aims to cover global prevalence, pathogenesis, diagnostic criteria, diagnostic tools, and both conventional and novel treatment options for FC in children.
**Methods:** This is a narrative review synthesizing published literature on FC in children. The authors conducted a pooled analysis of prevalence data from studies using Rome IV criteria, including 46,679 children across Asia, America, Europe, and Africa. They reviewed studies on epidemiology, pathophysiology, diagnostic approaches, and treatment modalities including pharmacological, non-pharmacological, and surgical interventions.
**Key Results:** The pooled global prevalence of FC in children using Rome IV criteria was 14.4% (95%CI: 11.2-17.6). By continent, Africa had the highest prevalence at 31.4% (3,283/10,458), followed by America at 12.1% (95%CI: 9.1%-15.1%), Europe at 8.3% (95%CI: 3.7%-12.9%), and Asia at 6.2% (95%CI: 1.3%-11%). Stool withholding behavior is the main pathophysiological mechanism, reported in 37%-91% of children with FC. Palpable fecal mass on abdominal examination occurs in 33%-68%, and fecal soiling in 33%-77%. For diagnosis, Rome IV criteria require symptoms for at least 1 month (reduced from 2 months in Rome III). Abdominal radiography has sensitivity of 60%-80% and specificity of 43%-99% for identifying constipation. The radiopaque marker colonic transit time study has sensitivity of 71% (95%CI: 57%-83%) and specificity of 95% (95%CI: 82%-99%). For treatment, polyethylene glycol (PEG) at 1-1.5 g/kg/day for 3-6 days is first-line for fecal disimpaction. PEG achieved disimpaction significantly faster than lactulose at day 2 (P=0.001). Adherence to therapy is low, with studies reporting only 38% and 37% of patients adhering. For maintenance, PEG is more effective than lactulose at increasing bowel movement frequency. Novel therapies include prucalopride (a 5-HT4 receptor agonist), lubiprostone (chloride channel activator), and linaclotide (guanylate cyclase-C agonist), though evidence in children remains limited. A multicenter RCT of prucalopride in 213 children found no significant improvement versus placebo. Lubiprostone in 606 children (Rome IV criteria) showed no significant difference in spontaneous bowel movement response rate versus placebo. Herbal medicines showed promise: Cassia fistula emulsion achieved 86.5% response rate vs 77.1% for PEG (RR=1.121, 95%CI: 0.939-1.338), with significantly higher defecation frequency (10.96±5.7 vs 6.9±3.5 stools/week, P<0.001). Pelvic physiotherapy plus standard medical care achieved treatment success in 88.5% vs 33.3% with standard care alone (P<0.001). Botox injections into the internal anal sphincter had an overall response rate of 70% in 164 children with intractable constipation. Transanal irrigation has an average success rate of 78% for both fecal incontinence and constipation.
**Clinical Implications:** FC is a clinical diagnosis based on Rome IV criteria; extensive testing is reserved for cases with alarm features or unclear diagnosis. Education about the pathophysiology (especially withholding behavior) and setting realistic expectations are essential to improve the low adherence rates (37-38%). Osmotic laxatives, particularly PEG, remain first-line therapy combined with structured toilet training using the child-oriented method starting at 18-24 months. For intractable cases, a multidisciplinary approach including pediatric gastroenterologists, nurses, psychiatrists, and surgeons may be needed. Novel pharmacological therapies and herbal medicines show promise but require more high-quality evidence before widespread adoption. Surgical options such as antegrade continence enemas are reserved for severe, refractory cases.