Kalloo first entered the peritoneal cavity via a gastrotomy in 2004 with an endoscope. A proposed paradigm shift from laparoscopy/laparotomy was anticipated by some, similar to that which had occurred on shifting from open surgery to minimally invasive surgery. This has not transpired as quickly or as widely as was hoped, for a number of reasons.

To a degree, certainly in children, this is an area that is still looking for an application which may make it superior to single‐port laparoscopy approaches. One might class some of the endoscopic therapeutic procedures detailed in this textbook as technically fulfilling the definition of natural orifice transendoluminal surgery (NOTES), for example transoral endoscopic fundoplication, peroral endoscopic myotomy (POEM), duodenal web division, etc. However, to truly be identified as a NOTES procedure, it really should operate in the extraluminal compartment, that is, the peritoneum.

Potential benefits are obvious as these procedures have a scarless result, may cause less catabolic stress to the patient and less postoperative discomfort and may consequently be associated with a shorter hospital stay.

Conversely, challenges remain significant to all those working in this rapidly changing field and include sepsis; lack of a triangulation approach for instruments when only one endoscope is employed – although with dual‐orifice approaches with two endoscopes from different angles, this is mitigated; an evolving but still relatively young/early instrumental toolbox for transendoscopic work (needle placers and endo‐scissors, etc. are constantly evolving, however); and closure of the port of entry – again, development of devices such as the over‐the‐scope clip (OTSC), endo‐clips which are rotatable and allow multiple open/close maneuvers, endo‐loops, etc. have almost solved this problem. Hemorrhage may be more easily contained with the advent of approaches such as Hemospray® but standard techniques such as argon plasma cautery, uni‐ or bipolar cautery or hot biopsy forceps and endo‐clips can also usefully be employed.

Challenges that set the child apart from the adult include different anatomy such as a more horizontal stomach, an intraabdominal bladder and proportionately larger viscera such as liver and spleen, so these factors may limit the working space available to the pediatric transluminal endoscopist. CO₂ insufflation is now standard for endoscopy in many units and hypercarbia does not seem to be an issue with endoscopy or laparoscopy using this gas.

Animal models for proof of concept are published with a number of ports of entry including oral, anal, vaginal, and combinations thereof. Procedures that have occurred in animal models include gastrojejunostomy; cholecystectomy; hysterectomy; direct visual liver biopsy; splenectomy; appendicectomy; and fallopian tube ligation.

Published work in adult humans with transgastric, transcolonic or transvaginal entry points includes appendectomy; cholecystectomy; hysterectomy; enteroenterostomy; lesion biopsy, etc.

In reality, there will increasingly be a blurring in the demarcations between the endoscopist and laparoscopist and indeed, a closer working relationship already exists in many centers with dual approaches, such as percutaneous laparoscopic‐assisted jejunostomy placement. The development of a specific specialist with both of these skills is well under way in larger centers. A successful model is likely to include a multidisciplinary combined effort involving endoscopists, laparoscopists, and radiologists providing real‐time imaging such as that which now occurs in MRI‐guided neurosurgery and the future application of robotics.

There has been concern that NOTES would be prematurely adopted and applied to children but there now exists a sufficient body of adult work which may suggest that targeted application of this technology is ready for the pediatric field. It goes without saying that close scrutiny of safety and efficacy will be paramount in the evolution in our speciality in order that these technologies find the right home, in the right hands, and thereby avoid discreditation by more traditional practitioners.