Introduction

There is a widely held view that endoscopy has revolutionized the approach to patients with inflammatory bowel diseases (IBD) as a pivotal tool in different steps of patient management. In the last few decades, gastrointestinal (GI) endoscopy has undergone significant developments in pediatrics in terms of technology and availability of pediatric‐size equipment, enabling comprehensive investigation of the GI tract in children.

Reporting of endoscopic disease activity should always include accurate descriptors of any abnormalities in each segment. However, due to variability between different operators, the scoring of endoscopic disease activity is becoming an important endpoint in clinical trials as well as in clinical practice. A wider application of the scoring system and the development of newer scores will help in management of pediatric IBD patients.

Diagnosis

Endoscopy remains the fundamental diagnostic tool for IBD in both adults and children. Ileocolonoscopy (IC) should include complete colonoscopy, and ileal intubation should always be advocated [1]. Sigmoidoscopy and partial colonoscopy are insufficient to explore disease extent and reach a definite diagnosis. Endoscopy of the ileocolon should be deferred in cases of toxic megacolon, while in cases of acute severe colitis, sigmoidoscopy or partial/full ileocolonoscopy might be considered in expert hands.

The Porto Criteria and ESPGHAN Paediatric Endoscopy Guidelines indicate on a strong evidence base that EGD should be performed in all children at the initial evaluation of disease irrespective of the presence or absence of upper gastrointestinal symptoms [2]. Endoscopic procedures in children should be performed according to recent ESPGHAN/ESGE recommendations [1]. As stated in the ECCO guidelines for histopathology in IBD, multiple biopsies from at least four sites along the colon (cecum, trasverse colon, sigmoid colon, rectum) and terminal ileum should be obtained and placed immediately in separate vials, accompanied by clinical information [3]. Multiple biopsies imply a minimum of two representative samples from each segment, including macroscopically normal segments. The Porto criteria also advocate multiple biopsies from esophagus, stomach, and duodenum in the EGD for all children with IBD irrespective of upper symptoms [2].

Establishing a definite and accurate diagnosis in a patient suspected of having IBD is mandatory. Therefore, a complete work‐up should be advocated. In patients transferred to a pediatric IBD unit without previously fulfilling Porto Criteria properly, a future strategy to complete the diagnostic work‐up should be planned, especially when a full ileocolonoscopy has not been performed. If successful treatment has been adequately initiated after the first endoscopy, complete fulfillment of the Porto Criteria could be postponed. Endoscopic findings can change over short periods of time. When a colonoscopy has shown only nonspecific findings, due to interruption or dissociation between endoscopy and histology, a new endoscopy should be completed, in order to better characterize the disease.

Monitoring

The usefulness of endoscopic reassessment should be individualized according to the disease type, severity, risk of relapse and risk of progression and in general, when a significant change in medical management is contemplated. Indeed, in pediatric IBD, the overall rate of management change after endoscopy can be up to 42% of cases [4]. Unfortunately, the appropriateness of periodic endoscopic reassessment after index ileocolonoscopy has never been formally studied and the value of it is much debated, especially in pediatric ulcerative colitis (UC). Indeed, treatment changes based on endoscopy are more frequent in children with Crohn’s disease (CD) than UC [5]. Clinical judgment and Pediatric Ulcerative Colitis Activity Index (PUCAI) have shown to be adequate for the evaluation of disease activity in pediatric patients. A PUCAI <10 has been closely associated with mucosal healing and not inferior to endoscopic evaluation in predicting clinically important outcomes [6,7]. Endoscopic appearance lags behind clinical improvement and may thereby underestimate response to treatment [8].

It does not seem justified to routinely recommend endoscopic assessment in pediatric UC solely for assessing disease activity, response to treatment or at relapse. Even though endoscopy is still considered the standard for evaluating disease activity in IBD, and used to confirm mucosal healing, it is invasive and costly [9]. However, endoscopic evaluation is mandatory in any case before major treatment changes (escalating and deescalating treatment strategies), for diagnosing complications (e.g., stenosis, dysplasia) and to exclude other diagnoses, such as ischemia and rarely infection, such as CMV [10].

In Clostridium difficile infection, evaluation by colonic endoscopy may be misleading in active colitis as typical pseudomembranes are commonly absent [11,12]. Moreover, full ileocolonoscopy is not recommended in severe colitis as the risk for serious complications, such as perforation, is higher even though it may be attempted safely in expert hands [13].

In colectomized patients, initial clinical suspicion of pouchitis should be confirmed by endoscopic evaluation of the pouch with mucosal biopsies. A clinical pattern of “irritable pouch syndrome” is characterized by increased stool frequency and cramping with normal pouch endoscopy and histology [14].

The benefit of postoperative endoscopy in CD has not been prospectively evaluated in children. A recent Australian study demonstrated that adults who underwent colonoscopy six months after surgery to decide on treatment adjustment had a considerably lower relapse at 18 months after surgery [15]. Extrapolation from these data in adults suggests that a similar protocol may also be necessary in pediatric patients to monitor for postoperative recurrence and treatment aimed at relapse prevention [16].

Reporting of endoscopic disease activity should always include accurate descriptors of any abnormalities in each segment [17]; however, due to the variability between different operators, the scoring of endoscopic disease activity is becoming an important endpoint in clinical trials [18–20]. Although validated endoscopic indexes are used in adults with IBD to assess mucosal healing, pediatric endoscopic endpoints to assess efficacy of medications in clinical trials are not clear. Validated scoring systems will be essential as investigators become more familiar with enrolling children into studies with endoscopic endpoints, such as mucosal healing. The distribution and severity of inflammation noted during endoscopy of children early in the course of IBD may be patchy, with a pattern that is less commonly seen in adults with IBD. For this reason, scoring systems used in adults may not easily be extrapolated to children.

However, despite their limitations, the use of endoscopic scoring systems can aid in reporting endoscopic findings and allow for easy comparisons between a patient’s current and previous endoscopy result. If it is feasible, the use of scores in clinical practice is recommended. However, documentation of endoscopic disease activity remains generally subjective in children. For this reason, if the endoscopic scoring systems are not used, it is important to report the following findings in each segment of the bowel: extent and location of inflammation; if bowel involvement is continuous or involves skip areas; presence of erythema; loss of vascular pattern; bleeding (contact or spontaneous); presence of erosions or ulceration (superficial or deep); and the presence of strictures or fistulae. In addition, on follow‐up endoscopy, it is important to note the degree of change of endoscopic activity since the previous evaluation.

A wider application of the scoring system and the development of newer scores will help with the comparison between drug efficacies and optimize a treat‐to‐target treatment algorithm in patient management of pediatric IBD.

Scoring systems