Since its introduction into clinical practice 15 years ago, capsule endoscopy (CE) has become the first-line investigation procedure in some small bowel pathologies, and more recently, dedicated esophageal and colon CE have expanded the fields of application to include the upper and lower gastrointestinal disorders. During this time, CE has become increasingly popular among gastroenterologists, with more than 2 million capsule examinations performed worldwide, and nearly 3000 PubMed-listed studies on its different aspects published. This huge interest in CE may be explained by its non-invasive nature, patient comfort, safety, and access to anatomical regions unattainable via conventional endoscopy. However, CE has several limitations which impede its wider clinical applications, including the lack of therapeutic capabilities, inability to obtain biopsies and control its locomotion. Several research groups are currently working to overcome these limitations, while novel devices able to control capsule movement, obtain high quality images, insufflate the gut lumen, perform chromoendoscopy, biopsy of suspect lesions, or even deliver targeted drugs directly to specific sites are under development. Overlooking current limitations, especially as some of them have already been successfully surmounted, and based on the tremendous progress in technology, it is expected that, by the end of next 15 years, CE able to perform both diagnostic and therapeutic procedures will remain the major form of digestive endoscopy. This review summarizes the literature that prognosticates about the future developments of CE.

The introduction of capsule endoscopy (CE) in clinical practice increased the interest for the study of the small-bowel. Consequently, in about 10 years, an impressive quantity of literature on indications, diagnostic yield (DY), safety profile and technical evolution of CE has been published as well as several reviews. At present time, there are 5 small-bowel capsule enteroscopy (SBCE) models in the worldwide market. Head-to-head trials have showed in the great majority of studies comparable results in terms of DY, image quality and completion rate. CE meta-analyses formed the basis of national/international guidelines; these guidelines place CE in a prime position for the diagnostic work-up of patients with obscure gastrointestinal bleeding, known and/or suspected Crohn's disease and possible small-bowel neoplasia. A 2-L polyethylene glycol-based purge, administered the day before the procedure, is the most widely practiced preparation regimen. Whether this regimen can be further improved (i.e., by further decreasing its volume, changing the timing of administration, coupling it with prokinetics and/or other factors) or if it can really affect the DY, is still under discussion. Faecal calprotectin has been used in SBCE studies in two settings: in patients taking non-steroidal anti-inflammatory drugs, to evaluate the type and extent of mucosal damage and, more importantly from a clinical point of view, in patients with known or suspected Crohn's disease for assessment of inflammation activity. Although there is still a lot of debate around the exact reasons of SBCE poor performance in various small-bowel segments, it is worth to remember that the capsule progress is non-steerable, hence more rapid in the proximal than in lower segments of the small-bowel. Capsule aspiration, a relatively unexpected complication, has been reported with increasing frequency. This is probably related with the increase in the mean age of patients undergoing CE. CE video review is a time-consuming procedure. Therefore, several attempts have been made to develop technical software features, in order to make CE video analysis easier and shorter (without jeopardizing its accuracy). Suspected Blood Indicator, QuickView and Fujinon Intelligent Chromo Endoscopy are some of the software tools that have been checked in various clinical studies to date.

The aim of this study was to determine the detection rate of the ampulla of Vater (AoV) during small bowel capsule endoscopy (SBCE) examinations and compare the two SBCE systems used in our center.

SBCE procedures performed in our center from March 2005 to June 2011 were reviewed retrospectively. A single reviewer, following a detailed protocol, analyzed 30 min of each recording to identify the AoV.

A total of 619 SBCE procedures were enrolled in the study, including 262 with a PillCam SB1, 148 with a PillCam SB2 and 209 with a MiroCam. AoV was identified in 59 SBCE examinations (9.5%), consisting of 28 with a PillCam SB1 (28/262, 10.7%), 13 with a PillCam SB2 (13/148, 8.8%) and 18 with a MiroCam (18/209, 8.6%) (P = 0.665). The AoV was visualized in 53.2 frames (median 12 frames, range 1-1056 frames); and the detection rate was low regardless of indication, patients' characteristics, SBCE system used or capsule transit parameters. Bile spout was associated with a higher AoV detection (P = 0.003).

The persistently low AoV detection rate using two different SBCE systems underlines the weakness of non-steerable capsule endoscopy. Furthermore, if AoV detection is taken as a surrogate marker of small polyp detection, it becomes obvious both that non-steerable SBCE cannot replace a side-viewing endoscope in the evaluation of periampullary polyps in familial adenomatous polyposis and that it is an infallible method in other small bowel polyposis states.

Now, more than 10 years after the approval of video capsule endoscopy (VCE), the technology has become an essential component in the management of several clinical conditions. Currently, two capsules are approved in the USA for visualizing the small bowel mucosa, one capsule is authorized for oesophageal assessment and several others are in use or under evaluation worldwide. New investigations have focused on optical improvements, advances in intestinal cleansing and risk reduction strategies to optimize VCE methodologies in clinical care. Established indications diagnosed using VCE include unexplained gastrointestinal bleeding, small bowel Crohn's disease (in adults and children >10 years old), localization of small bowel tumours and a broad range of miscellaneous abnormalities. Investigations are ongoing to determine the utility of VCE in colon cancer screening, assessment of oesophageal disorders and diagnosis of coeliac disease. Active research is in progress into ways to improve the efficacy of VCE recording interpretation, prolong imaging time and further enhance optics and imaging methods. To expand the potential utility of VCE, novel devices that can manoeuvre within or insufflate the gut lumen, tag or biopsy suspect lesions, or target drug delivery to specific sites are in development. To facilitate these advances, consortia have been organized to promote innovative VCE technologies.