Ultrasound is a routine diagnostic procedure widely used in gastroenterology departments worldwide, and gastrointestinal ultrasound (GIUS) has become increasingly important in diagnosing and following gastrointestinal disorders. Being a real-time imaging modality, it has some advantages over static imaging modalities such as CT and MRI, and it allows the examiner to perform various techniques and methods to enhance visualisation. GIUS requires more than essential ultrasound experience, and acquiring good images for correct interpretation can be challenging even for the experienced examiner. As such, there are several pitfalls that clinicians should be aware of. Based on our clinical experience with an evidence-based approach, we present the ten most common mistakes made in gastrointestinal ultrasound and how to avoid them.

Barrett’s oesophagus is a premalignant condition of the distal oesophagus predisposing to oesophageal adenocarcinoma. Given the potential for malignant progression and the poor prognosis of eosophageal adenocarcinoma when diagnosed at a symptomatic stage, patients with known Barrett oesophagus undergo regular endoscopic surveillance to detect neoplastic progression at an early and preferably endoscopically, treatable stage. Endoscopic management of early Barrett oesophagus neoplasia consists of a combination of endoscopic imaging, endoscopic resection and endoscopic ablation. Below we discuss a number of mistakes that are frequently made when managing Barrett oesophagus neoplasia and how to avoid them. Much of this discussion draws on existing guidelines (for background reading, check the ESGE Barrett oesophagus guideline), but in many instances the underlying evidence (even in the guideline) is missing and therefore many of our practically driven recommendations are based on common sense and our experience in this field.

Tissue sampling during endoscopic procedures is a fundamental aspect of investigating digestive diseases, with histological examination playing a crucial role in almost every case. Given its prevalence, the potential for mistakes is significant. Therefore, understanding the appropriate indications, techniques, and consequences of tissue sampling is essential for gastroenterologists. Key questions to consider before taking a biopsy or acquiring tissue include: Why? What for? How? How many?

This manuscript addresses these critical questions by detailing the eight most frequent and correctable mistakes in tissue acquisition during endoscopy. The recommendations provided are largely supported by existing guidelines and evidence, with some insights drawn from the authors' professional experience.