Prevalence of functional diarrhea in children and adolescents

Abstract

Background

Functional diarrhea (FDr) is a common disorder in toddlers and adults. In children, the Rome criteria define FDr as a disorder of children younger than 5 years old exclusively. However, in clinical practice, school‐aged children and adolescents sometimes consult for symptoms that mimic the diagnosis of FDr. We conducted a study aimed at assessing the prevalence of FDr in school‐aged children and adolescents.

Methods

A cross‐sectional study was conducted in children aged 8–18 years from two schools in Colombia. Children completed self‐report validated questionnaires to diagnose disorders of gut‐brain interaction (DGBI) per Rome IV (QPGS‐IV) for their age group and the questions related to FDr from the Rome IV questionnaire for infants and toddlers.

Key Results

After excluding children with organic diseases and IBS‐D, 981 participants were included (female 53.8%, White 24.7%, Indigenous 10.9%, mixed race 52.6%). Of the 981 participants, 325 (33.1%) had a DGBI. Of these, 17 children (5.2%) were diagnosed with FDr (3 participants 8–12 years; 14 participants 13–18 years). FDr was more prevalent among White children compared to non‐White children (mixed race, Black, and Indigenous) (p = 0.01).

Conclusion & Inferences

Despite the absence of FDr in the Rome IV criteria for children and adolescents, 1.7% of children aged 8–18 years likely have FDr. This study suggests that FDr does occur in children and adolescents. If confirmed in future studies, the diagnosis of FDr should be considered for inclusion in future editions of the Rome criteria for children of all ages.

This study, involving 981 children aged 8–18, found that 1.7% were diagnosed with functional diarrhea (FDr), despite its exclusion from Rome IV criteria for this age group. Highlighting the need for further studies to confirm these results.

Key points.

What's known?

• Functional diarrhea (FDr) in children is primarily recognized in toddlers according to the current pediatric Rome IV criteria.

What's new?

• This study provides evidence that symptoms suggesting FDr might also be present in school‐aged children and adolescents.

• By utilizing the Rome IV criteria adapted for children aged 8–18, the study found that 1.7% likely have FDr, challenging the current diagnostic criteria.

What's clinically relevant?

• The findings advocate for a revision of the Rome criteria for diagnosing FDr in the pediatric population, suggesting that clinicians should consider FDr as a potential diagnosis in older children and adolescents.

• Clinically, recognizing FDr across this broader age range can enhance diagnostic accuracy and management, leading to improved patient care and potentially reducing unnecessary or unfocused testing.

1. INTRODUCTION

Functional diarrhea (FDr) is a common disorder in young children. ¹ Studies from different countries found a prevalence of FDr of 1.9%–2.5% in children younger than 1 year of age, ² , ³ while studies in children 1–4 years of age found a prevalence of FDr of 1.5%–2.7%. ³ , ⁴ , ⁵ , ⁶ FDr is also seen in adult patients ⁷ and its diagnosis is established under the group of bowel disorders of the adult Rome IV criteria (Table 1). Adult‐based studies found a global prevalence of FDr of 4.7%. ⁸ In adults, FDr is thought to be part of a spectrum of disorders of gut‐brain interactions (DGBIs) that also includes irritable bowel syndrome‐diarrhea (IBS‐D), ⁹ , ¹⁰ a disorder that is also seen in children and adolescents (Table 1).

TABLE 1.

Rome IV diagnostics criteria for functional diarrhea (FDr) and IBS in children and adults.

Rome IV: Diagnostic criteria for FDr in children Daily painless, recurrent passage of four or more large, unformed stools Symptoms last more than 4 weeks Onset between 6 and 60 months of age No failure to thrive if caloric intake is adequate

Rome IV: Diagnostic criteria for IBS in children Abdominal pain at least 4 days per month associated with one or more of the following: Related to defecation Change in frequency of stool Change in form of stool In children with constipation, the pain does not resolve with resolution of the constipation After appropriate evaluation, the symptoms cannot be fully explained by another medical condition

Rome IV: Diagnostic criteria for FDr in adults Loose or watery stools, without predominant abdominal pain or bothersome bloating, occurring in more than 25% of stools. Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis Patients meeting criteria for IBS‐D should be excluded.

Rome IV: Diagnostic criteria for IBS adults Recurrent abdominal pain on average at least 1 day/week in the last 3 months, associated with two or more of the following criteria: Related to defecation Associated with a change in frequency of stool Associated with a change in form (appearance) of stool

To date, every version of the pediatric Rome criteria has been divided into two age groups, children up to 4 years and 4–18 years of age. FDr is not part of the pediatric criteria for children 4–18 years of age. The diagnosis was not included in this age group as it was thought to be only recognizable in younger children. ¹¹ However, in clinical practice, children and adolescents may sometimes consult for symptoms that mimic the diagnosis of FDr. Moreover, a large school‐based study conducted on adolescents in China found a prevalence of FDr of 5.4% applying the pediatric Rome III criteria to adolescents. ¹²

We conducted a school‐based study to establish whether FDr was present in children 8–18 years of age. We hypothesized that FDr would be present in this age group.

2. METHODS

Students 8–18 years of age from one public and one private school, located in Palmira and Cali Valle del Cauca, Colombia were invited to participate in a cross‐sectional study. Participants completed the Questionnaire of Pediatric Gastrointestinal Symptoms (Rome IV) corresponding to children 4–18 years of age and the questions inherent to the diagnosis of FDr related to the Rome IV criteria questionnaire for infants and toddlers. ¹³ Additionally, we included three questions to enable the identification of FDr in older children and adolescents and additional questions on past medical and family history (Appendix A). Children with a history of organic diseases or IBS‐D were excluded. Instructions on the questionnaires were given before completion by a member of the research team who was also available for any necessary clarification. The study was approved by the Ethics Committee of the Hospital Universitario del Valle “Evaristo García” in Cali, Colombia (024–2020, 2/27/2020).

2.1. Statistical analysis

Demographic data were calculated and included as mean and standard deviation (SD). Data were analyzed by gender, race/ethnicity and age group (school‐aged children, 8–12 years, and adolescents, 13–18 years). Categorical data were calculated using the chi‐squared test. Statistical significance was set at <0.05.

3. RESULTS

In total, 981 children, 8–18 years of age, completed the questionnaires (Figure 1). Participants had a mean age of 14.1 years (±1.9). The majority of participants were mixed race (52.6%) and 53.8% were females (Table 2). Of all the children surveyed, 325 (33.1%) participants met the diagnosis for a DGBI per Rome IV questionnaire for children older than 4 years of age. Of these, 24/325 (7.3%) were diagnosed with IBS. Following adult criteria that exclude IBS‐D from the diagnosis of FDr, 2 participants were excluded due to IBS‐D. Applying the Rome IV criteria for FDr, 17 participants (1.7%) have symptoms consistent with FDr. This represents, 5.2% of all children diagnosed with a DGBI.

FIGURE 1.

Flowchart of study enrollment for children.

TABLE 2.

Demographic characteristics (n = 981).

Age (years)
Mean (SD)	14.1 (±1.9)
Age of group
School age (8–12 years)	237 (24.2%)
Adolescents (13–18 years)	744 (75.8%)
Sex
Female	528 (53.8%)
Male	453 (46.2%)
Race
Mixed	516 (52.6%)
White	242 (24.7%)
Black	116 (11.8%)
Indigenous	107 (10.9%)
School
Public	228 (22.9%)
Private	756 (77.1%)
City
Cali	770 (78.5%)
Palmira	211 (21.5%)

We found no significant difference in sex among children likely to have FDr. Ten of the 453 (2.3%) male participants and 7 of the 528 female participants (1.4%) exhibited symptoms consistent with FDr (p = 0.33). Similarly, the prevalence did not significantly differ among age groups (1.3% in school‐aged children and 1.9% among adolescents) (Table 3). Symptoms consistent with FDr were more common among Whites (9 participants, 3.8%) compared with children than described themselves as non‐White (mixed races 7, Black 1, Indigenous 0) (p = 0.01) (Table 3).

TABLE 3.

Demographic characteristics of children diagnosed with functional diarrhea (FDr) (n = 981).

	Functional diarrhea
	No	Yes	p value
	(n = 964)	(n = 17)
Group of Age
School age	234 (98.7%)	3 (1.3%)	0.38
Adolescents	730 (98.1%)	14 (1.9%)
Sex
Male	443 (97.8%)	10 (2.3%)	0.33
Female	521 (98.6%)	7 (1.4%)
Race
Non‐white	731 (98.9%)	8 (1.1%)	0.01
White	233 (96.2%)	9 (3.8%)

4. DISCUSSION

Our study was aimed at assessing the presence of symptoms consistent with FDr in school‐age children and adolescents. As expected, children of both pediatric age groups displayed symptoms that meet the criteria for a likely diagnosis of FDr. The study suggests that in contrast with current assumptions, FDr may be present throughout the lifespan.

The current understanding of FDr in the pediatric population is mainly limited to young children. In this age group, FDr has been mostly linked to dietary practices like overfeeding and excessive consumption of juices rich in both fructose and sorbitol. ¹¹ Other studies have suggested that fructose exclusively, and not sorbitol, is responsible for triggering diarrhea after juice consumption in otherwise healthy toddlers. ¹⁴ Although, there are few pathophysiological studies on loose stools in healthy school‐age children and adolescents, juice consumption is not limited to toddlers and preschool children. Children 2–18 years of age consume a large proportion of their fruit intake as juice. ¹⁵ A study by our group found that 38% of children aged 8–18 years without organic diseases reported gastrointestinal symptoms associated with consumption of FODMAP. Thirty‐five percent of those children reported diarrhea. ¹⁶ Most of these children also reported abdominal pain despite not meeting criteria for IBS. This suggests that similarly to adults, FDr and IBS‐D may be part of a spectrum of disorders.

Children of all age groups consume large amounts of high corn syrup, which is rich on fructose, but also sucrose. ¹⁷ , ¹⁸ Over the last 20 years, there has been a greater understanding of the epidemiology, genetics, and pathophysiology of congenital sucrose‐isomaltase deficiency (CSID). Sucrose malabsorption leads to colonic fermentation, flatulence, and osmotic diarrhea. In addition to the classic homozygotic form, there are at least 37 SI variants that can reduce enzyme activity and cause gastrointestinal symptoms. ¹⁹ SI variants of CSID can present with symptoms that mimic those of IBS‐D and FDr. A multicenter study found hypomorphic SI variants in 4.5% of children experiencing chronic loose stools, ²⁰ from this 0.97% were older than 5 years old and 0.65% were adolescents.

Palsson et al. conducted a population‐based survey among adults from the US, Canada, and the United Kingdom, finding a prevalence of FDr ranging from 3.6% to 5.3% The pathophysiology of FDr in adults involves accelerated bowel transit, potentially amplified by stress and a previous episode of infectious gastroenteritis. ²¹ Studies have shown that stress is prevalent among adolescents and schoolchildren ²² , ²³ , ²⁴ , ²⁵ and as such, it might constitute a contributing factor for FDr in younger populations.

Our study has multiple strengths and limitations. This is the first study of FDr to include school‐aged children and apply the current version of the Rome criteria. The previous study from China, only studied adolescents using the Rome III criteria. Our study included a large sample size of 981 participants from different races and two different cities. Interestingly, our analysis revealed a higher prevalence of FDr among White children compared to non‐White children (mixed race, Black, and Indigenous) (p = 0.01). Knowing that some sucrose and lactose malabsorption are more predominant in certain races, this finding warrants further exploration to confirm our results and identify potential underlying factors contributing to this disparity. The limited sample size of our study does not allow us to draw conclusions; assure the generalizability to the entire population of Colombia or other countries. If the results of our study are confirmed in larger studies, well‐designed genetic and pathophysiological studies may help provide clarity to the possible significance of our findings. Additionally, while we acknowledge that our patients were not examined or measured by a medical practitioner or underwent testing, our study adhered to the methods established by the Rome Foundation in several epidemiological studies. ⁸ , ²⁶ , ²⁷

In conclusion, the study found that symptoms consistent with FDr were present in school‐age children and adolescents. The findings of our study have potential implications for both clinical practice and research. The recognition of this DGBI in children of all ages may help reassure patients and caretakers that the symptoms do not result from an undefined or dangerous disease and avoid unnecessary or unfocused testing. Our study may help inform future editions of the Rome criteria that could consider including the diagnostic criteria of FDr for children of all ages. Future studies should confirm our findings and investigate the possible overlap with other DGBI as well as the impact of FDr in quality of life of children.

AUTHOR CONTRIBUTIONS

Performed the research: Carlos Velasco‐Benitez and Daniela Velasco. Designed the research study: Carlos Velasco‐Benitez and Daniela Velasco. Analyzed the data: Carlos Velasco‐Benitez and Daniela Velasco. Wrote the paper: Miguel Saps, Amber Balda, and Samantha Arrizabalo.

FUNDING INFORMATION

This research received no external funding.

CONFLICT OF INTEREST STATEMENT

No competing interests declared.

INFORMED CONSENT

Informed consent was obtained from all subjects involved in the study.

Supporting information

Data S1:

Velasco‐Benitez C, Velasco D, Balda A, Arrizabalo S, Saps M. Prevalence of functional diarrhea in children and adolescents. Neurogastroenterology & Motility. 2025;37:e14950. doi: 10.1111/nmo.14950

DATA AVAILABILITY STATEMENT

The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy and ethical restrictions.