Endoscopic assessment of terminal ileum in screening colonoscopy: is it worth the effort?

Krzysztof Dąbkowski; Maciej Tryba; Ernest Biesiada; Kamila Konczanin; Małgorzata Michalak; Magdalena Szczygłowska; Krzysztof Safranow; Teresa Starzyńska

doi:10.5946/ce.2025.018

Articles

Page Path: HOME > Clin Endosc > Volume 58(5); 2025 > Article

Original Article Endoscopic assessment of terminal ileum in screening colonoscopy: is it worth the effort?: Krzysztof Dąbkowski¹, Maciej Tryba¹, Ernest Biesiada¹, Kamila Konczanin¹, Małgorzata Michalak¹, Magdalena Szczygłowska¹, Krzysztof Safranow², Teresa Starzyńska¹; Clinical Endoscopy 2025;58(5):731-737.
DOI: https://doi.org/10.5946/ce.2025.018
Published online: July 17, 2025

¹Department of Gastroenterology, Pomeranian Medical University, Szczecin, Poland

²Department of Biochemistry, Pomeranian Medical University, Szczecin, Poland

Correspondence: Krzysztof Dąbkowski Department of Gastroenterology, Pomeranian Medical University, Szczecin, Poland Ul. Unii Lubelskiej 1, 71-252 Szczecin, Poland E-mail: dabkowskikrzysztof@wp.pl

• Received: January 12, 2025 • Revised: March 1, 2025 • Accepted: March 9, 2025

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

2,412 Views
137 Download
1 Web of Science
1 Crossref

prev next

Full Article

Download PDF

Abstract
Graphical abstract
INTRODUCTION
METHODS
RESULTS
DISCUSSION
NOTES
REFERENCES

See letter "Terminal ileum in screening colonoscopy: routine practice or risk-stratified approach?" in Volume 58 on page 696.

Abstract

Background/Aims:
Screening colonoscopies often do not include terminal ileum assessment. In this study, we examined how often endoscopists assessed the terminal ileum during screening colonoscopy, how it influenced the procedure time and patient comfort, and whether it revealed pathological findings.
Methods:
We retrospectively analyzed the screening colonoscopy examinations performed in our department between 2017 and 2021. We retrieved the procedure duration (minutes), patient age and sex, pain scale, and screening colonoscopy results.
Results:
A total of 2,449 screening colonoscopy examinations were performed between 2017 and 2021. The patients were classified into one of two groups: the cecum reached or the terminal ileum intubated. These two groups did not significantly differ in sex or reported pain score, while the patients were significantly younger (55.2±6.5 vs. 56.2±6 years, p=0.015) and the colonoscopy duration was longer (22.8±9.8 vs. 18±10.5 min, p<0.001) in the terminal ileum group. Pathological conditions (nonspecific inflammatory lesions) in the small intestine were reported in 5/297 patients.
Conclusions:
Small intestine intubation was associated with a significantly longer colonoscopy duration and revealed pathological conditions of no apparent clinical significance.
Keywords: Colonoscopy; Mass screening; Small intestine

Graphical abstract

INTRODUCTION

Colonoscopy is a basic medical tool used for the assessment and treatment of colorectal diseases. The quality performance measures of colonoscopy are divided into pre-procedure, intra-procedure, and post-procedure quality measures according to the European Society of Gastrointestinal Endoscopy (ESGE); a similar classification is followed by the American Society of Gastrointestinal Endoscopy (ASGE).¹^,² Both societies designate the cecal intubation rate as a marker of colonoscopy completeness, with minimum and target standards of cecal intubation rate set as ≥90% (for all examinations according to ESGE) and ≥95% (for screening according to ASGE).¹^,² To consider a colonoscopy complete, the cecum and its landmarks should be fully visualized.¹^,² For the purpose of neoplasia detection, the terminal ileum should be intubated only when the visualization of typical cecal landmarks is not possible, or if the endoscopist is uncertain whether the cecum was entered.¹^-³

Ileoscopy is not a part of routine colonoscopy, and studies have shown that the small intestine is assessed in only 5% to 15% of colonoscopy examinations.⁴^-⁶ Notably, the terminal part of the small intestine can be a site of various inflammatory and neoplastic diseases, such as neuroendocrine tumors and lymphoma. Terminal ileum intubation is considered a time-consuming and difficult task, and is thus not routinely performed.⁶^,⁷ However, study results generally show that small intestine intubation is safe, with a relatively short learning curve, and adds only a few minutes to the whole procedure.⁶^,⁸ In symptomatic patients, ileoscopy has a diagnostic yield of 20% to 40%, and there is a general consensus that the terminal ileum should be intubated in patients with symptoms.³^,⁹^-¹¹ However, different researchers have varied opinions; moreover, study results differ regarding its utility for the detection of pathological lesions in asymptomatic patients.¹²^,¹³

In the present study, we aimed to investigate how frequently endoscopists assessed the small intestine during screening colonoscopy, whether they detected pathological findings in the terminal ileum, and how this procedure influenced the examination time and pain experienced during the examination.

METHODS

We performed a retrospective analysis of screening colonoscopy examinations performed in our departments (tertiary center and university hospitals) between 2017 and 2021. Our aim was to evaluate how often endoscopists assess the terminal ileum in screening colonoscopy, how this practice influences the procedure time and patient comfort (pain), and whether it reveals pathological findings (inflammatory and neoplastic diseases, especially neuroendocrine tumors). Patients were recruited according to the Polish Colonoscopy Screening Program criteria. The individuals included in the study were asymptomatic, aged between 50 and 65 years, or younger, or had a first-degree relative with colorectal cancer. Patients with symptoms suggesting colon cancer or inflammatory bowel disease and those in whom conscious sedation (benzodiazepines, opioids) or deep sedation with propofol was used were excluded from the present study, due to the paucity of sedated cases. The endoscopists performing the screening colonoscopy had experience in performing at least 3,000 colonoscopies, and the decision to intubate the small intestine was left to their discretion.

The included patients were divided into two groups: patients in whom only the cecum was intubated and those in whom the small intestine was reached. We retrieved the procedure duration (the “scope in-scope out” time in minutes), patient age (years), sex, extent of examination (colon vs. small bowel), and screening colonoscopy results from our computer database. A pain scale from 1 (least severe) to 4 (most severe) was obtained from a survey completed by the patients immediately after the examination. All examinations were performed by gastroenterology specialists with several years of experience in performing colonoscopy.

Statistical analyses were performed using Statistica 13 (TIBCO). The nonparametric Mann-Whitney U-test was used to compare patient age, examination time, and pain scores. The χ² test with Yates’ correction was used to compare the sex distribution and frequency of reporting most severe pain between small intestine and cecum group. Data are expressed as number (percentage), and mean±standard deviation and range and median with interquartile range where appropriate. A p-value of <0.05 was considered significant.

Ethical statements

The study was performed in accordance with the relevant guidelines and regulations. All data were collected as part of the routine diagnosis and treatment. Informed consent for the procedure and General Data Protection Regulation information were obtained and provided to the patients. The need for ethics board approval was waived by the Pomeranian Medical University Bioethics Committee owing to the retrospective and non-interventional study design.

RESULTS

A total of 2,449 screening colonoscopy examinations were performed between 2017 and 2021. The cecum was intubated in 2,403 patients (cecal intubation rate, 98.1%). The 46 patients in whom the cecum was not intubated were excluded from the study. Figure 1 presents the patient enrollment and exclusion criteria.

The terminal ileum was intubated in 297 (12.1%) patients. Comparative analysis (Table 1) revealed that the two groups did not significantly differ in the sex distribution (p=0.76) or the patient-reported pain during the procedure (p=0.26), while the patients in the terminal ileum group were significantly younger than those in the cecum group (55.2±6.5 vs. 56.2±6 years, p=0.015), and colonoscopy duration was significantly longer in the terminal ileum group (22.8±9.8 vs. 18±10.5 min, p<0.001). No complications were observed in either group. Subdivision of the patients according to pain score (Table 2) showed that the majority of patients with the most severe pain were in the cecum group (p=0.005).

Among the 297 cases of terminal ileum intubation, pathological conditions in the small intestine were described in only 5 (1.7%). These five cases included four cases of nonspecific inflammatory lesions (2 aphthae, one erosion, and one erythema), and one case of nodular hyperplasia. Typical findings are presented in Figure 2. No tumors, including neuroendocrine tumors, were observed. The biopsy results were unremarkable or demonstrated nonspecific chronic or active lymphocytic ileitis. None of these five patients developed inflammatory bowel disease during the mean follow-up of 25.2 (9–51) months.

Overall, small intestine intubation was performed in a minority of screening colonoscopy examinations and was associated with a significant increase in colonoscopy duration. Terminal ileal assessment revealed several pathological conditions that were not clinically significant.

DISCUSSION

The need for terminal ileum intubation during colonoscopy remains a matter of ongoing debate.³ On one hand, the terminal ileum is a site of various inflammatory and neoplastic diseases, including neuroendocrine tumors; on the other hand, terminal ileum intubation is generally perceived by endoscopists as a time-consuming and difficult task.⁷ Although the small intestine is a potential site of both malignant and inflammatory diseases, the colonoscopy quality measures proposed by American and European societies set the cecal intubation rate as the marker of examination completeness and do not include ileocecal valve intubation and terminal ileum assessment.¹^,²

Routine assessment of the terminal ileum is reportedly performed in only 5% to 15% of examinations,⁵^,⁶^,¹³ which is in line with our present findings that the small intestine was intubated in 12% of the cases in our study. In the hands of experienced endoscopists, small intestine intubation adds only a few minutes to the whole procedure time.⁸ Accordingly, in our present study, procedure duration was the only significant difference between the examined groups (cecum vs. small intestine), with the ileoscopy adding a median of 6 minutes to the examination time. Previous studies have shown that valve morphology influences intubation success (easiest in volcano-like and hardest in thin-lipped) and that the rates of successful intubation are higher in experienced endoscopists than in trainees.⁶^,⁸ Complications of ileoscopy have been reported in case reports rather than in studies, which generally demonstrate the safety of ileoscopy,⁶ as shown in our present study. According to other studies, the reasons for the small percentage of terminal ileum intubations include additional time, difficulty, patient discomfort, or awareness of the relatively low number of pathological findings in the terminal ileum.⁷

In our study, ileoscopy revealed pathological conditions in 1.7% of the asymptomatic patients. Recently performed studies report that the frequency of pathological findings is higher among symptomatic patients (5% to 11%) compared to in asymptomatic patients (2.7% to 3.3%), and that the diagnostic yield of ileoscopy is higher in patients with diarrhea and reaches 40% in patients with suspected inflammatory bowel diseases.⁵^,⁶^,⁸^,¹⁴ The indication for colonoscopy influences the diagnostic yield of ileoscopy, and previous findings support the need to perform routine ileocolonoscopy in patients with symptoms, such as anemia, diarrhea, hematochezia, and abdominal pain, or suspicion of tuberculosis.³^-⁵^,¹⁵^,¹⁶ Similar to the present study, the most commonly reported pathological findings are nonspecific lesions in the terminal ileum, including aphthae, erosions, and ulcers, followed by inflammatory lesions that lead to diagnosis of Crohn's disease and other lesion types (ischemic, infectious, and drug-related).⁵ The safety of ileoscopy, the fact that it adds only a few minutes to the whole procedure, what was presented in our study, and significant diagnostic yield in symptomatic patients, should encourage the endoscopists to at least try to intubate the terminal ileum in patients with ailments suggesting small bowel diseases.

Scarce data are available regarding the natural history of accidental nonspecific inflammatory terminal ileum findings. This includes signs of diseases such as inflammatory bowel disease, infectious diseases, rheumatoid disorders, and drug-related mucosal injuries. In a multicenter study, Kim et al.¹⁷ evaluated 134 asymptomatic patients with biopsied inflammatory terminal ileum lesions, and reported that the majority disappeared or decreased (73.8%) on colonoscopic follow-up. A lack of improvement was significantly associated with ulcers having a star shape, and the majority of patients were smokers or heavy alcohol consumers, or took medications (non-steroidal anti-inflammatory drugs [NSAIDs], aspirin, and clopidogrel)¹⁷ Different findings have been reported among symptomatic patients with ulcerations in the terminal ileum, which are a manifestation of a specific disease that is diagnosed within a follow-up of 3 to 6 months (59.5% Crohn disease, 25.7% NSAID-induced ulcers, 12.2% intestinal tuberculosis, and 6.8% eosinophilic enteritis).¹⁸

Studies have also reported neoplastic findings in screening colonoscopies, including neuroendocrine tumors in the colon and small bowel.¹²^,¹³^,¹⁹^,²⁰ In a recent study, we identified seven patients with rectal neuroendocrine tumors among 10,000 screening examinations (1 in every 1,500 colonoscopies).¹⁹ Data from an English colonoscopy cancer screening program (colonoscopies in patients with positive fecal occult stool test) revealed 146 neuroendocrine tumors (rectal, colonic, and ileal) in 216,707 colonoscopies.¹³ Among the diagnosed tumors were 30 ileal tumors, including 23 tumors with nodal metastases and 11 with distal metastases.¹³ Kooyker et al.¹² investigated histopathological examinations from screening colonoscopies performed in the years 2014–2016 in the Netherlands, which revealed 54 neuroendocrine tumors in the rectum and 11 neuroendocrine tumors in the colon.

In contrast, some reports have shown little value of routine ileal intubation in screening colonoscopy. A study by Kennedy et al.²¹ included over 6,000 patients, and demonstrated abnormal endoscopic findings in only 1% of the patients and histopathological abnormalities in only 0.3% of the patients, supporting the concept that ileoscopy rarely provides clinically relevant information. The authors concluded that routine ileoscopy should not be a part of routine screening examinations. Accordingly, other studies have demonstrated only minor benefits and a lack of cost-effectiveness of routine assessment of the small intestine, with abnormal findings in only 0.3% to 1% of cases.⁶^,²¹^-²³ The discrepancies between studies may be partly explained by differences in the qualifications for screening colonoscopy—for example, a two-step procedure (colonoscopy only after a positive fecal occult blood test, as in the English program) vs. a one-step qualification (colonoscopy based only on age and family history, as in our study).

Our present findings are in line with previous demonstrations that significant findings in the terminal ileum are rarely uncovered in asymptomatic patients.²¹^,²⁴ We also found that endoscopists rarely make an effort to intubate the small intestine. Partially, this could be explained by the fact that the majority of patients with the most severe pain (pain score 4) were in the cecum group, which could be a factor leading to a waiver of terminal ileum intubation and one of the study limitations. Similarly, the higher frequency of terminal ileum intubation in younger individuals observed in our study may be attributed to the fact that colonoscope insertion is generally easier in younger than in older patients. This could be due to reduced loop formation and greater colonic elasticity in younger individuals and the presence of diverticula, postsurgical adhesions, and a higher risk of complications in older patients.²⁵^,²⁶

Finally, our study has several limitations that must be noted. These include its retrospective design, the relatively small sample size despite being a screening colonoscopy study, the limited diversity of the endoscopists performing the procedures, and the criteria applied for case enrollment. Each of these aspects may have affected the study's results and the extent to which the conclusions can be generalized.

In conclusion, small intestine intubation was performed in a minority of screening colonoscopy examinations and was associated with a significant increase in the colonoscopy duration. Terminal ileum assessment did not reveal neoplastic conditions and showed only a few inflammatory conditions that were not clinically significant.

Conflicts of Interest

The authors have no potential conflicts of interest.

Funding

None.

Author Contributions

Conceptualization: KD, TS; Data curation: MT, EB, KK, MM, MS; Formal analysis: KD, TS, KS; Investigation: MT, EB, KK, MM, MS; Methodology: KD, TS; Project administration: KD, TS; Resources: MT, EB, KK, MM, MS; Supervision: KD, TS; Validation: KS; Visualization: KD, KS; Writing–original draft: KD; Writing–review & editing: all authors.

Fig. 1.

Flowchart of patient enrollment and exclusion from the study.

Fig. 2.

Endoscopic pictures of the terminal ileum with erosions (A), nodular hyperplasia (B), and aphthous lesions (C).

Table 1.

Comparative analysis of patients in whom the cecum or small intestine was intubated on colonoscopy

	Cecum	Small intestine	All	p-value
Total	2,106 (100.0)	297 (100.0)	2,403 (100.0)
Age (yr)	56.2±6 (26–66)	55.2±6.5 (30–65)	56,1±10.5 (26–66)	0.015
Time (min)	18±10.5 (1–90)	22.8±9.8 (2–54)	18.6±6.1 (1–90)	<0.001
Pain score 1–4	1.8±0.8 (1–4)	1.7±0.6 (1–4)	1.7±0.7 (1–4)	0.26
Male/female ratio	791 (37.6)/1,315 (62.4)	128 (43.1)/169 (56.9)	919 (38.2)/1,484 (61.8)	0.76
Complications reported	No	No	No

Values are presented as number (%) or mean±standard deviation (range).

Table 2.

Division of the patients according to the pain score

	Pain score
	1–3	4	1–4
Cecum	2,019 (95.9)	87 (4.1)	2,106
Ileum	295 (99.3)	2 (0.7)	297
Total	2,314	89	2,403

Values are presented as number (%). p=0.005 for difference between the cecum and ileum group (chi-square test with Yates correction).

REFERENCES

1. Rex DK, Schoenfeld PS, Cohen J, et al. Quality indicators for colonoscopy. Gastrointest Endosc 2015;81:31–53.Article PubMed
2. Kaminski MF, Thomas-Gibson S, Bugajski M, et al. Performance measures for lower gastrointestinal endoscopy: a European Society of Gastrointestinal Endoscopy (ESGE) quality improvement initiative. United European Gastroenterol J 2017;5:309–334.Article PubMed PMC PDF
3. Neilson LJ, Bevan R, Panter S, et al. Terminal ileal intubation and biopsy in routine colonoscopy practice. Expert Rev Gastroenterol Hepatol 2015;9:567–574.Article PubMed
4. Mari A, Khoury T, Mahamid M, et al. The yield of ileoscopy: does indication matter? Isr Med Assoc J 2020;11:684–687.PubMed
5. Meral M, Bengi G, Kayahan H, et al. Is ileocecal valve intubation essential for routine colonoscopic examination? Eur J Gastroenterol Hepatol 2018;30:432–437.Article PubMed
6. Iacopini G, Frontespezi S, Vitale MA, et al. Routine ileoscopy at colonoscopy: a prospective evaluation of learning curve and skill-keeping line. Gastrointest Endosc 2006;63:250–256.Article PubMed
7. Ansari A, Soon SY, Saunders BP, et al. A prospective study of the technical feasibility of ileoscopy at colonoscopy. Scand J Gastroenterol 2003;38:1184–1186.Article PubMed
8. Cherian S, Singh P. Is routine ileoscopy useful?: an observational study of procedure times, diagnostic yield, and learning curve. Am J Gastroenterol 2004;99:2324–2329.Article PubMed
9. Morini S, Lorenzetti R, Stella F, et al. Retrograde ileoscopy in chronic nonbloody diarrhea: a prospective, case-control study. Am J Gastroenterol 2003;98:1512–1515.Article PubMed
10. Shah RJ, Fenoglio-Preiser C, Bleau BL, et al. Usefulness of colonoscopy with biopsy in the evaluation of patients with chronic diarrhea. Am J Gastroenterol 2001;96:1091–1095.Article PubMed
11. Geboes K, Ectors N, D’Haens G, et al. Is ileoscopy with biopsy worthwhile in patients presenting with symptoms of inflammatory bowel disease? Am J Gastroenterol 1998;93:201–206.Article PubMed
12. Kooyker AI, Verbeek WH, van den Berg JG, et al. Change in incidence, characteristics and management of colorectal neuroendocrine tumours in the Netherlands in the last decade. United European Gastroenterol J 2020;8:59–67.Article PubMed PDF
13. Basuroy R, O’Donnell CM, Srirajaskanthan R, et al. Ileocolonic neuroendocrine tumours identified in the English bowel cancer screening programme. Colorectal Dis 2018;20:O85–O91.Article PubMed PDF
14. Jeong SH, Lee KJ, Kim YB, et al. Diagnostic value of terminal ileum intubation during colonoscopy. J Gastroenterol Hepatol 2008;23:51–55.Article PubMed
15. Misra SP, Dwivedi M, Misra V, et al. Endoscopic biopsies from normal-appearing terminal ileum and cecum in patients with suspected colonic tuberculosis. Endoscopy 2004;36:612–616.Article PubMed
16. Misra SP, Misra V, Dwivedi M. Ileoscopy in patients with ileocolonic tuberculosis. World J Gastroenterol 2007;13:1723–1727.Article PubMed PMC
17. Kim JH, Lee JY, Park YE, et al. Clinical course of terminal ileal ulcers observed incidentally during colonoscopy. Dig Dis Sci 2021;66:4423–4428.Article PubMed PDF
18. Mehta V, Gupta A, Mahajan R, et al. Symptomatic isolated terminal ileal ulcers: etiology and clinical significance. Endosc Int Open 2017;5:E539–E546.Article PubMed PMC
19. Dąbkowski K, Michalska K, Rusiniak-Rosińska N, et al. Rectal neuroendocrine tumors in a colon cancer screening colonoscopy program. Sixteen-year single institution experience. Scand J Gastroenterol 2023;58:310–313.Article PubMed
20. Dąbkowski K, Rusiniak-Rossińska N, Michalska K, et al. Endoscopic treatment of rectal neuroendocrine tumors in a 13-year retrospective single-center study: are we following the guidelines? Pol Arch Intern Med 2021;131:241–248.Article PubMed
21. Kennedy G, Larson D, Wolff B, et al. Routine ileal intubation during screening colonoscopy: a useful maneuver? Surg Endosc 2008;22:2606–8.Article PubMed PDF
22. Kundrotas LW, Clement DJ, Kubik CM, et al. A prospective evaluation of successful terminal ileum intubation during routine colonoscopy. Gastrointest Endosc 1994;40:544–546.Article PubMed
23. Yoong KK, Heymann T. It is not worthwhile to perform ileoscopy on all patients. Surg Endosc 2006;20:809–811.Article PubMed PDF
24. Emami MH, Behbahan IS, Zade HD, et al. New interpretation for diagnostic yield of ileoscopy: a prospective study and a brief review. J Res Med Sci 2009;14:157–163.PubMed PMC
25. Lin OS. Performing colonoscopy in elderly and very elderly patients: risks, costs and benefits. World J Gastrointest Endosc 2014;6:220–226.Article PubMed PMC
26. Loffeld RJ, Liberov B, Dekkers PE. Yearly diagnostic yield of colonoscopy in patients age 80 years or older, with a special interest in colorectal cancer. Geriatr Gerontol Int 2012;12:298–303.Article PubMed

Figure & Data

REFERENCES

Citations

Citations to this article as recorded by

Terminal ileum in screening colonoscopy: routine practice or risk-stratified approach?
Seong-Jung Kim
Clinical Endoscopy.2025; 58(5): 696. CrossRef

PubReader
ePub Link

Cite

CITE: export Copy Download Format; Close

Download Citation

Download a citation file in RIS format that can be imported by all major citation management software, including EndNote, ProCite, RefWorks, and Reference Manager.