The inability to establish the exact location of the capsule in the small intestine, and the inability of flushing or suctioning, makes an adequate bowel cleansing of particular importance for the SBCE. Debris, biliary secretion, bubbles and blood, especially in the distal small bowel, and failure of the capsule to reach the cecum have the potential to limit the diagnostic yield [25].

Since cleaning the small intestine prior to examination may improve the diagnostic yield, CE preparation regimen s—mainly based on the same products adopted for colonoscopy preparation—have been proposed [26]. But the optimal preparation regimen is still unclear [27–30]. A clear liquid diet and an overnight fast appear to be associated with poor visibility of the terminal ileum in the majority of patients [31]. A combination of simethicone and PEG has frequently been promulgated as an effective means to increase the visibility of the small intestine [32–37]. Simethicone seems to improve mucosal visualization and tolerability by reducing air bubbles, flammable gas (namely, hydrogen), and abdominal discomfort [38].

The only pediatric study to date prospectively evaluated 198 patients with five different preparation regimen s [39]. The mucosal visibility was assessed, at relative time points after the pylorus by dividing the small bowel transit time into five segments. Mucosal visibility was thus compared to relative similar levels of the small intestine. Mucosal visualization improved significantly after preparation with PEG and simethicone. In the most distal part of the ileum, which is the portion most often affected by debris, the use of 1.75 g/25 ml/kg or 3.5 g/50 ml/kg of PEG solution (70 g/1000 ml) prior to CE resulted in better visibility. Despite the improvement in mucosal visualization, there was not a significant difference in the overall diagnostic yield within the study groups. However, a slight difference between the group with only diet and group with PEG and simethicone could be seen in the terminal ileum (last segment divided by time).

Patient discomfort was also evaluated in this study and the group with 25 ml/kg (up to 1 L/die) of PEG solution seemed to be able to obtain the same results of the group with 50 ml/kg of PEG, but with half the quantity required.

No significant differences were found regarding gastric and small intestinal transit times or in the proportion of patients in whom the cecum was not visualized. However, the intestinal transit is much faster in children than adults and therefore, bowel preparation might not impact intestinal transit time in the pediatric age group.

Thus, 1.75 g/25 ml/kg (up to 1 L) of PEG solution (70 g/1,000 ml) the night before the procedure plus 20 mL (376 mg) oral simethicone 30 min before capsule ingestion appears to be the preparation of choice for SBCE in children . This preparation regime seems to improve the mucosal visualization, especially in the terminal ileum, without discomfort for children , and reduces the intestinal secretions by the addition of simethicone.

A meta-analysis [3] and additional reports from pediatric literature [4, 5] includes 995 patients who underwent 1,013 CE procedures with positive findings in 511 (61.4 %; 95 % confidence interval [CI] = 52.7–69.7 %). Studies were complete (i.e., the capsule reached or passed the ileocecal valve by the end of the recording period) in 846 procedures (86.0 %; 95 % CI = 81.6–89.9 %; P = 0.0003) [3–5]. In many other studies, diagnostic findings have been achieved even though the capsule did not enter the colon [10, 14, 15, 20]. A new diagnosis was established in 162 patients (66.0 %; 95 % CI = 45.4–83.9 %) with a change in therapy for 101 of the patients (71.3 %; 95 % CI = 45.2–91.5 %) where those parameters were quantified.

A total 824 (88.4 %) children in the studies for which ingestion was reported swallowed the capsule uneventfully (95 % CI = 86.4–90.3 %; P < 0.0001) [13]. The youngest was age 4 years [20]. Only one patient in the reports could not swallow the capsule and refused endoscopic placement, although this is not an infrequent occurrence in clinical practice [9].

CD was the most prevalent diagnostic outcome of SBCE studies performed in the pediatric population, based on the criteria of at least three mucosal ulcers as previously reported by Fireman and colleagues [40] and Mow and colleagues [41]. In various studies, a change in medical therapy resulted for 75–92 % of patients with known CD [10, 11, 14]. In one study, SBCE examination in one study reclassified four of five patients with UC and one of two patients with IC (total five of seven, or 71 %) to CD due to newly diagnosed small bowel mucosal lesions [10]. In pediatric patients investigated for OGIB or IDA by SBCE , 38.4 % had confirmed diagnoses [13]. This compares with 59.4 % positive results in adults [42]. Forty-six lesions were diagnosed by SBCE: [6, 7, 8, 9, 11, 15] 15 vascular malformation s; 7 CD ; 14 nonspecific enteropathies; 3 polyps; 2 marked lymphoid hyperplasias; and 1 case each of Meckel’s diverticulum , nonsteroidal anti-inflammatory drug–induced lesions, lymphangiectasia, leukemia-related and graft-versus-host disease. In patients younger than age 8 years, there were four cases of polyps, two of angiodysplasias, two blue rubber bleb hemangiomas, two Meckel’s diverticula, one anastomotic ulcer, and one intestinal duplication [20]. In the adult meta-analysis, vascular abnormalities also were the most common cause of OGIB (50 %), followed by inflammation and ulcers (27 %), and neoplasia (9 %) [42]. Evaluation of polyposis syndromes accounted for 8.0 % of the indication s in 81 pediatric patients, with positive results in 80.2 % of procedures compared to adult diagnostic yield of 55.9 % for neoplastic lesions [42]. Although SBCE is rarely performed for the evaluation of malabsorption, it is useful since intestinal lymphangiectasia can appear beyond the reach of the endoscope [3]. The scalloped, swollen folds and mosaic pattern seen in adults with celiac disease is infrequently seen in pediatric patients undergoing SBCE [43]. Its infrequency in pediatric patients may reflect the infrequency of CE use for evaluation of malabsorption in this population [2] or the decreased time of gluten exposure and potentially patchy or very subtle mucosal changes in childhood at histological levels of Marsh I or II, for which the sensitivity of CE is low [44]. Lymphonodular hyperplasia and intussusceptions are often seen. Although they can be clinically significant in certain situations, they are normally nonpathogenic conditions indigenous to the pediatric population [3].

Capsule retention in the small bowel occurred in 18 and gastric retention occurred in 4 of 1013 procedures, producing a pooled retention rate of 2.3 % (n = 22/1013; 95 % CI = 1.5–3.4 %; P = 0.4247) [3, 4, 5, 13]. Endoscopy was used to remove five capsules including four from the stomach [8, 14] and one from an ileal pouch [3]; 13 were retrieved surgically while taking appropriate measures to mitigate the cause of the retention [6, 8, 11, 12, 14]. A retained capsule was successfully evacuated by bowel prep at 22 days post-ingestion [8].

The highest risk factors for capsule retention include known IBD (5.2 % risk), previous SBFT demonstrating small bowel CD (35.7 % risk) and a body mass index below the fifth percentile combined with known IBD (43 % risk), although retention has occurred despite the absence of stricture on SBFT [12]. Among four patients with CD having capsule passage lasting longer than 5 days (with three continuing on to retention), there was a difference in age being significant (18.8 ± 0.9 vs. 14.6 ± 3.5), but not height or weight compared to patients who did not have retention [14]. Retention rates for indication s of OGIB, CD, and neoplastic lesions were 1.2 % (95 % CI = 0.9–1.6 %; P = 0.6014), 2.6 % (95 % CI = 1.6–3.9 %), and 2.1 % (95 % CI = 0.7–4.3 %), respectively, with a pooled rate of 1.4 % (95 % CI = 1.2–1.6 %) for those procedures [42]. On a per-procedure basis, this pattern is in adults, where retention in OGIB, CD, and polyps occurs at rate of 1.4, 2.2, and 1.2 %, respectively. Thus, it appears that the risk of retention is dependent on the clinical indication and not age. Rare cases of perforation, aspiration, or small bowel obstruction have been reported in adults but none have been reported in children . Minor mucosal trauma has occurred in children in which capsules were placed with the Roth net [18]. A specific capsule placement device is now available (AdvanCE, US Endsocopy, Mentor, OH [45]).

The majority of capsule retention s have occurred in patients with normal small bowel radiological studies, yet functional patency may be present in patients with radiologically documented strictures. An identically sized capsule containing a mixture of barium and lactose and radiofrequency identity tag was developed to test functional patency and gradually implode intact PC passage does not occur within 30 h.

A retrospective study reviewed 23 patients with known (n = 14) or suspected (n = 9) pediatric CD who underwent evaluation with the PC prior to using the video capsule [3]. Of the 19 who were evaluable, patency was established and subsequent CE was performed successfully in all but one who had a retained capsule from CE the following week.

In a single-center prospective pediatric trial that evaluated 18 patients (age 10–16 years) who ingested the PC, 15 excreted an intact PC (mean 34.5 h) [46]. The 18 cases included five known CD, three IC , one UC, and nine suspected CD . CD was eventually diagnosed in all patients having PC transit of more than 40 h and in 9 of 12 who passed the PC in 40 h or less. There were no capsule retention s or adverse event s. Thus, the PC can serve as a useful guide and may lessen the likelihood of CE retention, particularly in known CD where the risk of retention is greatest.

SBCE is a useful diagnostic tool that has particular benefit in pediatrics , because it is an imaging modality that does not require the ionizing radiation, deep sedation, or general anesthesia . The risk of retention appears to be dependent on indication rather than age and parallels the adult experience by indication , making SBCE a relatively safe procedure with a significant diagnostic yield.

Esophageal capsule endoscopy (ECE) was approved by the US FDA and introduced for clinical use in 2004. A second iteration of the capsule, Pillcam ESO 2 (Given Imaging ), widened the field of view; increased the frame rate to 18 images per second; and improved the image quality with two additional lenses, higher spatial resolution and a wider dynamic range, was approved by the US FDA in 2007.

However, its use in pediatrics —or at least in clinical trials and the retrospective reporting of that use—have been limited. Only two small pediatric trials of the first ECE capsule have been reported. Both focused on portal hypertension [47, 48]. In the first trial, which also included young adults, 27 of the 28 ECEs were complete, each averaging a total recording time of 20 min and a mean esophageal transit of 192 s (range, 4–631) [47]. Esophageal varices were small in 10 (37 %), medium to large in 4 (17 %), and negative in 13 (48 %), with gastric varices in 10 (37 %). Of note, other esophageal and duodenal findings also identified.