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Page 2 of 7 Bojórquez et al. Mini-invasive Surg 2023;7:8 https://dx.doi.org/10.20517/2574-1225.2022.65

80% of patients exhibiting small bowel (SB) involvement. Therefore, the visualization of the small intestine
[1]
can be considered an obligatory exploration .
The most frequently used techniques to explore the small intestine in patients with CD are small bowel
capsule endoscopy (SBCE), small bowel ultrasound (IUS) and MR enterography (MRE). These techniques
have similar diagnostic yields except for proximal SB involvement, where SBCE has proven to be
[2,3]
superior . Furthermore, proximal SB CD has been associated with poorer outcomes, highlighting the
importance of an early diagnosis and selecting an appropriate initial treatment approach .
[4]

ROLE OF SMALL BOWEL CAPSULE ENDOSCOPY IN SUSPECTED CROHN’S DISEASE
WHY? The typical endoscopic findings in CD are inflammatory lesions with a discontinuous distribution,
strictures, fistulae, and perianal disease. Furthermore, it has been described that detecting at least three
ulcers in SBCE highly suggests CD, provided the patient has not recently used non-steroidal anti-
[2]
inflammatory drugs . Among the benefits of SBCE, its ability to detect SB mucosal defects, assess disease
activity and location and translate these findings into indexes like the Lewis Score and the Capsule
Endoscopy Crohn’s Disease Activity Index (CECDAI) are noteworthy. The use of indexes is highly
[1,5]
recommended to help categorize the disease, monitor activity and aid in treatment selection . SB
inflammatory activity was evaluated using the Lewis score in a small series of patients with unclassified
inflammatory bowel disease (IBD-U). SBCE influenced reclassification to CD in approximately 25% of cases
and after a mean follow-up of 42 months, only 28% of patients remained with IBD-U .
[6]
Kopylov et al. conducted a meta-analysis of 13 studies comparing the diagnostic yield of SBCE to MRE and
IUS in detecting SB inflammatory activity. The results suggest that there are no significant differences in the
ability of each diagnostic modality to detect SB inflammation in suspected CD .
[7]
WHEN? In most cases of suspected CD, positive findings on ileocolonoscopy (IC) help confirm the
diagnosis. SBCE aids in establishing a CD diagnosis by describing disease extension and activity. It is also
useful when IC is inconclusive and to determine SB involvement other than distal terminal ileum. Samuel et
al. reported the endoscopic skipping of the distal terminal ileum in more than half of suspected CD patients
when evaluated with a SBCE [1,5,8] .

MONITORING CROHN’S DISEASE WITH SMALL BOWEL CAPSULE ENDOSCOPY
WHY? Monitoring patients with established CD aims to achieve early recognition of disease flares, identify
endoscopic or transmural response and guide treatment escalation, de-escalation or switch. The preferred
treatment outcome is mucosal healing as it has been associated with less overall morbidity . Mucosal
[2,3]
healing can be assessed indirectly through cross-sectional imaging and non-invasive fecal and serological
markers or by direct mucosal visualization, where capsule endoscopy has a leading role. In a study by
Gonzalez-Suarez et al., SBCE showed higher sensitivity for detecting proximal and distal disease (77% vs.
[9]
45%) compared to MRE . Furthermore, the use of SBCE in monitoring established CD has been studied,
and according to several studies, capsule findings may lead to a change in Montreal classification and affect
management in more than half of the patients [7,9,10] . Additionally, capsule endoscopy is deemed cost-
effective, and can be perceived as more comfortable when compared to MRE, which is especially important
for long-term follow-up [11,12] .

WHEN? The current ECCO-ESGAR guidelines suggest that 12 to 24 weeks after treatment initiation is the
appropriate timing for mucosal healing reevaluation .It is also recommended to perform mucosal healing
[2]
reevaluation when there is suspicion of treatment failure that may require a switch of therapy, when a