Abstract
Background
Dolichocolon (DC) is an underrecognized anatomic variant associated with constipation; its association with ulcerative colitis (UC) is unknown.
Methods
We retrospectively reviewed abdominal MRI and CT scans in children with UC, Crohn’s disease (CD), and non-inflammatory bowel disease (non-IBD) controls, classifying DC subtypes.
Results
A total of 111 cases (66 with UC) were examined. DC was similarly common (p = 0.4436) in patients with constipated (69%) or non-constipated (NC-UC: 57%) UC. In non-constipated (NC) patients, DC prevalence was higher in children with UC than those with CD or controls. Type 1 DC predominated in NC children with proctitis/left-sided UC (E1/E2), while Type 2 DC was enriched in children with extensive/pancolitis (E3/E4).
Discussion
DC may be associated with different phenotypes of UC and may influence disease distribution independent of constipation. However, given the cross-sectional design of this study, these associations should be interpreted cautiously and require confirmation in longitudinal studies.
Keywords: Children, Redundant colon, Phenotype modifier, Constipation, Inflammatory bowel disease
Introduction
Dolichocolon (DC), an underrecognized anatomic variant characterized by redundancy of the large intestine, is strongly associated with functional constipation in both pediatric [1, 2] and adult [3] populations, but emerging observations [4] link it with other common gastrointestinal disorders as well. In adults, DC has been subclassified into three types: cranial displacement of the sigmoid loop relative to the iliac crests (Type 1), caudal displacement of the transverse colon below the iliac crests (Type 2), and redundant loops at the hepatic or splenic flexures (Type 3) [3]. Due to ambiguity in defining Type 3 DC, we have limited diagnostic consideration in pediatric cases to Types 1 and 2 [1] based on contrast enema studies. Our recent findings demonstrating high DC prevalence in infants with constipation [1] supported previous observations [5] suggesting DC as typically congenital in children [1]. Furthermore, we recently observed the significantly increased prevalence of Type 1 DC in pediatric patients with perianal Crohn’s disease [6], raising the possibility that it may differentially associate with IBD subtypes in children.
A recent study [7] found that children with ulcerative colitis (UC), particularly those with proctitis (Paris classification [8]: E1) or left-sided colitis (E2), had a higher prevalence of constipation compared to those with extensive (E3) or pancolitis (E4), or Crohn’s disease (CD), aligning with our own clinical observations. Given that both DC and UC have been associated with constipation in children, we sought to examine the relationship between DC and disease extent in children with UC. We hypothesized that DC may contribute mechanistically not only to the increased prevalence of constipation in children with UC but also to the disease process itself.
Methods
IRB/IACUC Approval
The study was performed under institutional IRB-approved protocols (H-43969, H-50062) of Baylor College of Medicine.
Identification of Participants
In this single center study, we searched our electronic medical record system (EMR) between May 2020 and May 2025 with diagnosis terms of ‘ulcerative proctitis’, ‘ulcerative pancolitis,’ ‘Crohn’s disease of the small and large intestine,’ and ‘blunt force abdominal trauma,’ as well as ‘magnetic resonance enterography’ (MRE) to identify subgroups for the study. Data were obtained using SlicerDicer within the Epic EMR (Epic Systems Corporation, Verona, WI). Approximately 10–20% of patients with E1/E2 UC patients experience proximal extension within 6 months from diagnosis [9, 10]. Therefore, we only included children without progression toward extensive UC for at least 6 months of diagnosis.
We first studied the overall prevalence of DC in children with UC. However, since DC has been strongly associated with constipation [1], we further stratified the patients based on the presence or absence of a history of constipation and subsequently compared non-constipated cases to non-constipated controls.
Diagnosis of Dolichocolon
MRE (in children with IBD) and CT scans (in children with blunt force abdominal trauma; non-IBD controls) were studied for the presence of DC. DC was defined as any portion of the sigmoid colon reaching above the iliac crest line (Type 1[3]), and/or any portion of the transverse colon reaching below the iliac crest line with or without redundant flexures (Type 2[3]). We decided not to study Type 3[3] DC (i.e., redundant loops at the hepatic or splenic flexure) in detail because that category was deemed to be arbitrary/imprecise. A single experienced observer (RK) made the diagnoses.
Statistics
DC prevalence was analyzed as a dichotomous variable using Fisher’s exact (FE) test (GraphPad Prism, Dotmatics, Boston, MA, USA). Group sizes were determined arbitrarily given the exploratory nature of this discovery study. Statistical significance was defined as p < 0.05.
Results
Description of Participants
A total of 111 subjects were included in the study: 39 with left-sided UC, 27 with extensive UC, 20 non-constipated children with L3 Crohn’s disease (CD), and 25 non-constipated trauma controls.
Among the 66 children with UC, 29 (44%) had a history of constipation. This was significantly more common in children with left-sided UC than in those with extensive UC (56% [22/39] vs. 26% [7/27], p = 0.0226).
Prevalence of Dolichocolon in Children with UC
We first examined the prevalence of DC in our pediatric UC cohort. The overall prevalence of DC on MRE was 62% (41/66). This did not differ significantly between children with E1/E2 disease (69% [27/39]) and those with E3/E4 disease (52% [14/27]; p = 0.1993). Similarly, DC prevalence was not significantly different between constipated UC (C-UC) and non-constipated UC (NC-UC) children (69% [20/29] vs. 57% [21/37]; p = 0.4436) (Fig. 1A).
Fig. 1.
Dolichocolon (DC) may associate with pediatric ulcerative colitis (UC) phenotype in non-constipated patients. A The overall prevalence of DC in UC was 62% and was not significantly influenced by disease extent or history of constipation. Prevalence was 69% in left-sided disease (E1/E2) compared with 52% in extensive/pancolitis (E3/E4; p = 0.1993), and 69% in constipated UC (C-UC) compared with 57% in non-constipated UC (NC-UC; p = 0.4438). None of these group differences were statistically significant. B UC extent type did not significantly associate with DC type in the complete group of patients with UC (p = 0.2315). C DC was significantly more commonly present in E1/2 NC-UC (n = 17), and E3/4 UC (n = 20), than in patients with ileocolonic (L3, n = 20) Crohn’s disease (CD) (p = 0.0023 and p = 0.0407, respectively), or otherwise healthy patients with blunt force abdominal trauma (control: Ctrl; n = 25) (p = 0.0035, and p = 0.0231, respectively). D The prevalence of Type 1 vs. Type 2 DC (alone or in combination) significantly separated between patients with E1/2 NC-UC or E3/4 NC-UC (p = 0.0019). P values were calculated in GraphPad Prism (Dotmatics, 225 Franklin Street, Floor 26 Boston, MA 02110, USA) by Fischer’s exact testing
The overall distribution of DC subtypes was also similar between children with left-sided and extensive UC (p = 0.2315) (Fig. 1B).
Prevalence of Dolichocolon in Children with NC-UC
Because DC prevalence in children with UC was not significantly associated with a history of constipation, we hypothesized that DC may be differentially associated with IBD subtypes independent of constipation.
To test this, we compared DC prevalence, including subtype distribution, among NC children with E1/E2 UC, E3/E4 UC, and NC L3 CD (n = 20), as well as non-IBD trauma controls (Ctrl, n = 25) without documented chronic disorders (including constipation) and with normal intestinal anatomy on CT (Table 1).
Table 1.
Dolichocolon (DC) prevalence with subtype distribution between non-constipated patient groups
| Non-constipated (NC) patient cohorts | E1/E2 UC (NC)A | E3/E4 UC (NC)B | L3 CD (NC)C | Ctrl (NC)D |
|---|---|---|---|---|
| N | 17 | 20 | 20 | 25 |
| Age (mean); ± stdev | 14.6; ± 2.2 | 14.2; ± 2.3 | 12.7; ± 2.2 | 12.6; ± 3 |
| DC* (% of N) | 11 (65)C,D | 10 (50)C,D | 3 (15) | 4 (16) |
| Type 1 | 7 (41)B,C,# | 2 (10) | 2 (10) | 3 (12) |
| Type 2 | 3 (18) | 5 (25)* | 1 (5) | 1 (4) |
| Combined type 1 and 2 | 1 (6) | 3 (15) | 0 | 0 |
| Type 1 and Combined | 8 (47)C,D | 5 (25) | 2 (10) | 3 (12) |
| Type 2 and Combined | 4 (24) | 8 (40)C,D | 1 (5) | 1 (4) |
CD Crohn’s disease, Ctrl otherwise healthy, blunt force abdominal trauma patients (these patients had CT with contrast performed as trans-sectional abdominal imaging as opposed to the other groups who had MRI enterography performed as standard of care), N number of patients, NC no history of constipation, stdev standard deviation. Age is in years of age when the trans-sectional imaging was performed. Italic and bold: p ≤ 0.05; italic p < 0.1. Letters in superscript designate p ≤ 0.05 between the column’s group and the letter specified group. #p < 0.1 when group A was compared to group D. *p < 0.1 when group B was compared to group D. P values were calculated in GraphPad Prism (Dotmatics, 225 Franklin Street, Floor 26 Boston, MA 02110, USA) by Fischer’s exact testing
DC prevalence was significantly higher in children with NC-UC than in those with L3 CD or controls (57% vs. 15% and 16%, respectively; p < 0.01). DC was also more common in both E1/E2 and E3/E4 NC-UC groups compared with L3 CD and non-IBD controls (Fig. 1C).
Notably, combined Type 1 and Type 2 DC (Fig. 2) was observed exclusively in children with UC and was not identified in CD or control cohorts.
Fig. 2.
Complex DC (Type 1 [white arrow] and Type 2 [gray arrow] simultaneously, as demonstrated in a case on the MRI enterography image) was uniquely present only in patients with UC in this cohort
The higher prevalence of DC in E1/E2 NC-UC was primarily driven by Type 1 DC, whereas Type 2 DC was more prominent in the E3/E4 NC-UC group (Fig. 1D).
Discussion
Consistent with prior clinical observations [7], we observed a relatively high prevalence of constipation history (44%) in our cohort of children with UC, particularly among those with left-sided disease. We also identified a high prevalence of DC (62%) in children with UC, numerically exceeding that of constipation, although this difference did not reach conventional statistical significance (p = 0.0547). These findings raised the possibility that this anatomic variant of the large intestine may be relevant to UC in children, particularly in the context of underlying genetic and environmental susceptibility to IBD (see below). Therefore, we stratified children with UC based on the presence or absence of a history of constipation and subsequently compared NC cases to NC controls. This approach was intended to determine whether DC is associated with UC even independent of clinically evident constipation. We reasoned that such stratification could help identify a shared underlying mechanistic link between UC and constipation. The persistence of an association between DC and UC, even in the absence of clinically significant constipation, further supported the potential relevance of this relationship, although its nature remains to be clarified.
Our results in NC groups suggest that DC may be associated not only with the presence of UC, but potentially with its anatomic distribution in pediatric patients. Specifically, Type 1 DC may be more frequently observed in left-sided disease, whereas Type 2 DC may be more common in extensive UC or pancolitis. These patterns may indicate a potential role for DC in influencing the regional distribution of inflammation within the colon (Fig. 1D).
As DC results in increased colonic length without corresponding increases in volume [3], it may expand epithelial surface area and augment host-microbiome interactions relevant for IBD pathogenesis [11–13], which may induce autoimmunity in susceptible segments. Segmental redundancy may lead to intermittent mechanical kinking and fluctuating epithelial oxygenation in the colon, potentially amplifying localized inflammation [14] and favoring a UC phenotype over CD in genetically and environmentally predisposed individuals. Recent organoid studies have shown elevated epithelial oxygen consumption and hypermetabolic stress in UC [15], consistent with our hypothesis that even subtle DC-associated vascular compromise could predispose to disease initiation and segmental expansion in susceptible individuals.
While UC and CD share many genetic and environmental risk factors [16], our observations are the first to suggest that DC may influence UC phenotype in over 50% of the cases. These findings may help explain not only the development of UC in the context of IBD susceptibility but also the persistence of segment-specific disease in a subset of patients. Thus, our discovery findings can set the nidus for potential interventions that may prevent the development of UC in children at increased risk for the disease, such as those with first-degree relatives suffering from IBD [17]. Early recognition of DC in such children may improve adherence to dietary, lifestyle [18], and bowel management interventions, strategies that can optimize colonic function and potentially reduce UC risk.
We acknowledge the limitations of our study, particularly its cross-sectional design, which precludes establishing causal relationships. Although DC appears to be associated with UC and its subtypes in children, the precise nature of this relationship cannot be determined from the present data. Further investigation is therefore warranted to clarify the mechanistic and clinical implications of DC in the pathogenesis of IBD.
Acknowledgments
R.K. was supported by the Gutsy Kids Fund, graciously maintained by Brock Wagner, the Klaasmeyers, the Frugonis, and other generous donor families.
Author Contributions
RK contributed to conceptualization, acquisition and analysis of data, manuscript drafting, and final submission; DPB contributed to graphics and critical revision; RGS contributed to conceptualization and critical revision.
Funding
R.K. is a member of the Texas Medical Center, Digestive Disease Center funded by the NIH (NIDDK P30 DK 56338 Center for Gastrointestinal Development, Infection and Injury).
Data Availability
The datasets generated and/or analyzed during the current study are not publicly available due to institutional policies, but are available from the corresponding author on reasonable request.
Declarations
Conflict of interest
The authors declare no competing interests.
Footnotes
The manuscript has been submitted to medRXiv preprint server: https://doi.org/10.1101/2025.08.20.25333704. Graphic abstract: Created with BioRender by D. Berens.
Publisher's Note
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References
- 1.Simon D, Berens D, Zambrana Valenzuela R et al. Dolichocolon is common in pediatric gastroenterology patients with constipation and associated complaints. J Pediatr Gastroenterol Nutr. 2026;82:407–414. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Vattimo A, Burroni L, Bertelli P, Messina M, Meucci D. Tota G (1993) Total and segmental colon transit time in constipated children assessed by scintigraphy with 111In-DTPA given orally. J Nucl Biol Med 1991;37:218–222. [PubMed] [Google Scholar]
- 3.Dilmaghani S, Lupianez-Merly C, Fetzer J, BouSaba J, Halawi H, Camilleri M. Colon Volume by Computed Tomography and Scintigraphic Colonic Transit in Constipated Patients With or Without Redundant Colon. Clin Gastroenterol Hepatol. 2024;22:e2322. [DOI] [PubMed] [Google Scholar]
- 4.Sharma RP, Kusnik A, Ravi D et al. S2149 Too Much of Gut Gives You Reflux. Official journal of the American College of Gastroenterology|ACG. 2022;117:e1459–e1460. [Google Scholar]
- 5.Raahave D. Dolichocolon revisited: An inborn anatomic variant with redundancies causing constipation and volvulus World. J Gastrointest Surg. 2018;10:6–12. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Kellermayer R, Szigeti RG, Sammer M, Vogel AM, Winter HS. Type 1 Dolichocolon as a Potential Anatomic Co-morbidity in Children with Perianal Crohn’s Disease Dig Dis Sci. 2026. [DOI] [PMC free article] [PubMed]
- 7.Cenni S, Colucci A, Salomone S et al. The prevalence of constipation in children with new diagnosis of inflammatory bowel disease: A retrospective study. J Pediatr Gastroenterol Nutr. 2025;80:799–806. [DOI] [PubMed] [Google Scholar]
- 8.Levine A, Griffiths A, Markowitz J et al. Pediatric modification of the Montreal classification for inflammatory bowel disease: the Paris classification. Inflamm Bowel Dis. 2011;17:1314–1321. [DOI] [PubMed] [Google Scholar]
- 9.Hochart A, Gower-Rousseau C, Sarter H et al. Ulcerative proctitis is a frequent location of paediatric-onset UC and not a minor disease: a population-based study. Gut. 2017;66:1912–1917. [DOI] [PubMed] [Google Scholar]
- 10.Martinelli M, Fedele F, Romano C et al. Disease course of ulcerative proctitis in children: A population-based study on behalf of the SIGENP IBD Group. Dig Liver Dis. 2024;56:70–76. [DOI] [PubMed] [Google Scholar]
- 11.Fofanova TY, Petrosino JF, Kellermayer R. Microbiome-Epigenome Interactions and the Environmental Origins of Inflammatory Bowel Diseases. J Pediatr Gastroenterol Nutr. 2016;62:208–219. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Kellermayer R, Zilbauer M. The Gut Microbiome and the Triple Environmental Hit Concept of Inflammatory Bowel Disease Pathogenesis. J Pediatr Gastroenterol Nutr. 2020;71:589–595. [DOI] [PubMed] [Google Scholar]
- 13.Nagy-Szakal D, Hollister EB, Luna RA et al. Cellulose supplementation early in life ameliorates colitis in adult mice. PLoS One. 2013;8:e56685. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Colgan SP, Campbell EL. Oxygen metabolism and innate immune responses in the gut. J Appl Physiol 1985;2017:1321–1327. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Ojo BA, Heo L, Fox SR et al. Patient-derived colon epithelial organoids reveal lipid-related metabolic dysfunction in pediatric ulcerative colitis. Nat Commun. 2025;16:11026. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Kellermayer R. Challenges for epigenetic research in inflammatory bowel diseases. Epigenomics. 2017;9:527–538. [DOI] [PubMed] [Google Scholar]
- 17.Kim HJ, Shah SC, Hann HJ et al. Familial Risk of Inflammatory Bowel Disease: A Population-Based Cohort Study in South Korea. Clin Gastroenterol Hepatol. 2021;19:e2115. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Yang X, Ding S, Liu S. Association of Leisure-Time Physical Activity Patterns With Constipation: Evidence From the National Health and Nutrition Examination Survey. Am J Gastroenterol. 2025;120:1865–1869. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets generated and/or analyzed during the current study are not publicly available due to institutional policies, but are available from the corresponding author on reasonable request.