Relevance and costs of constipation as the only cause of functional gastrointestinal disorders in childhood: prospective observational study in clinical practice

BACKGROUND: Functional gastrointestinal disorders (FGIDs) are common in children of all ages and have a considerable impact on the patient’s quality of life, on the families and on the health care system costs. Recent data indicate that both overt and occult constipation may have a causative role in most cases. OBJECTIVE: The main objective is to establish the prevalence of both overt and occult constipation as the only cause of most FGIDs. DESIGN: Observational prospective study. All patients with overt or occult constipation were treated with polyethylene glycol (PEG ) at disimpaction dose followed by maintenance dose and then reassessed at two months follow-up. SETTING: Tertiary pediatric gastroenterology outpatient clinic. PARTICIPANTS: All consecutive patients referred to the outpatient clinic between January and July 2018, aged 4-18 years, with FGIDs according to Rome IV criteria. Patients with gastrointestinal alarm features were excluded. Of 272 patients accessing the clinic, 209 were excluded because of not fulfilling the eligibility criteria, 63 consecutive patients were enrolled in the study, none refused to participate, 45 completed the follow-up up to now. EXPOSURE: Patients were treated with PEG 1.5 gr/Kg/day for 3 days, then with half dose for 2 months. MAIN OUTCOMES AND MEASURES: The hypothesis being tested was formulated before the data collection. The main endpoint was defined as a decrease of more than an half in frequency and severity of FGIDs, by using pain severity and pain frequency scores. RESULTS: Prevalence of functional constipation (FC) according to Rome IV was 63.5%, PEG treatment prescribed to all patients suffering for at least one FGID was successful in 42 patients (93%). The difference between the prevalence of FC according to Rome IV criteria and the prevalence of constipation as the only cause of FGIDs was highly significant (p<0.001). CONCLUSION AND RELEVANCE: Results support the hypothesis that overt or occult constipation is the main significant cause of most FGIDs. For the first time, results highlight the relationship between constipation and irritable bowel syndrome (IBS) with diarrhea and IBS mixed type. These findings may result in an improved management of children with FGIDs and in a substantial decrease of health care costs.