Functional constipation: A common and often overlooked cause for abdominal pain in children

The most common causes for chronic pain abdomen in pediatric practice are functional abdominal pain disorders, a subgroup of functional gastrointestinal disorders under the Rome IV classification. Constipation is usually associated with painful defecation, but abdominal pain as a predominant or presenting symptom of functional constipation (FC) is not very well recognized. We conducted this study to ascertain the prevalence of FC in chronic pain abdomen and proportion of FC children presenting with predominant complaints of pain abdomen. Prevalence of FC and functional abdominal pain was ascertained separately over a 1-year in children > 4 years of age in our hospital. The number of children with FC presenting with abdominal pain was noted. Abdominal pain site and duration were noted in the FC group and were compared with those in the functional abdominal pain group to find out any significance. Diagnosis was based on Rome IV criteria, but relevant investigations to rule out organic pathology were done whenever clinically indicated. The prevalence of abdominal pain was 22% in our gastroenterology service and that of FC was 27%. Among the children presenting with chronic abdominal pain, FC was seen in 10% of the patients and functional abdominal pain disorders in 34%. Among children presenting with constipation, 12% had pain as the sole complaint. However, some form of pain or pain as one of the symptoms was seen in 47.5%.  FC is a major cause for abdomen pain in children and is often overlooked. Not attributing pain to constipation may delay the diagnosis, which may have poor prognosis.