Mistakes in... booklet 2019 out!
The booklet in 2019 contains eight most recent Mistakes in… articles, covering a wide range of topics.
Mistakes in... session at UEG Week 2019
Learn from experts about mistakes in the gastroenterology field and how to avoid them.
Mistakes in decompensated liver cirrhosis and how to avoid them
Protecting against future decompensation episodes is key
Patients with early stages of chronic liver disease and even those with compensated cirrhosis can present without any clinical symptoms, which means that liver disease and ongoing liver damage can remain unidentified for many years. However, morbidity and mortality drastically increase once the stage of ‘decompensated cirrhosis’ has been reached.1,2 Decompensated cirrhosis describes the development of clinically overt signs of portal hypertension and/or impairment of hepatic function (e.g. variceal bleeding, ascites or overt hepatic encephalopathy). The first hepatic decompensation event significantly increases the risk that further complications of liver cirrhosis and decompensation episodes will occur.2 Moreover, individuals who have advanced stages of liver cirrhosis are four times more susceptible to infection, which is, in turn, the most frequent trigger of hepatic decompensation.3,4
Mistakes in chronic hepatitis B management and how to avoid them
All patients require long-term monitoring.
Hepatitis B virus (HBV) infection is the most common chronic viral infection in the world. Despite the availability of a preventative vaccine, more than 250 million people worldwide are chronically infected with HBV. The complications of chronic HBV infection—cirrhosis and hepatocellular cancer (HCC)—account for more than 850,000 deaths per year.1 HBV is transmitted haematogenously and sexually, with the majority of HBV infections being transmitted vertically (or perinatally) in high prevalence regions.2 HBV infection acquired at birth or in early childhood results in chronicity in >95% of cases, whereas only 5–10% of those who are infected in adulthood will progress to chronic infection.
Mistakes in the management of ECF and how to avoid them
Gl fistulae can be one of the most challenging complications of intestinal disease to manage
Gastrointestinal fistulae can be one of the most challenging complications of intestinal disease to manage. These abnormal tracts connect the epithelialised gut surface to either another part of the gut, another organ or tissue, or to the skin (table 1). This connection can cause enteric contents to bypass important absorptive surfaces, resulting in insidious malnutrition or overt diarrhoea, infection within other organs or the exquisitely embarrassing occurrence of having faeculant material in a woman’s vagina or on a person’s skin. Understandably, this can have a major impact on a person’s quality of life and psychological wellbeing and hamper overall prognosis in terms of general health and wellbeing. Through careful multidisciplinary management of the situation much can be done to address the fears and expectations of patients: careful stoma management, medical therapies to control output, nutritional support and consideration of the central role that surgery plays in resolving a fistula.

Mistakes in refractory coeliac disease and how to avoid them
Assessing adherence to a GFD and the initial coeliac disease diagnosis are important
Refractory coeliac disease (RCD) is characterized by the persistence or recurrence of symptoms and signs of malabsorption associated with villous atrophy in patients with coeliac disease who have adhered to a strict gluten-free diet (GFD) for more than 12 months.1–3 Serology is usually negative or, in a small percentage of cases, positive at a low titre.4 Splenic hypofunction, a risk factor for RCD, can be indicated by Howell–Jolly bodies and pitted red cells in a peripheral blood smear. A reduced spleen size visible on ultrasound examination also provides direct evidence of hyposplenism.5


Mistakes in the management of carbohydrate intolerance and how to avoid them
Carbohydrates not absorbed in the small intestine are fermented by colonic bacteria to organic acids and gases1 (e.g. carbon dioxide, hydrogen and methane), part of which is absorbed in the colon, the other part remaining in the lumen.2,3 Large interindividual differences have been demonstrated for the production of such acids and gas.4,5 Carbohydrate malabsorption can be diagnosed by using the hydrogen breath test, because the gases produced after administration of a provocative dose of carbohydrate are unique products of bacterial carbohydrate fermentation.6,7
Mistakes in enteral stenting and how to avoid them
Indications include stenosis (oesophageal and colonic) and gastric outlet obstruction
Gastrointestinal stent placement was introduced at the end of the nineteenth century when it was performed in patients who had a malignant oesophageal obstruction.1 Nowadays, gastrointestinal stents are placed for multiple indications, such as oesophageal stenosis (Figure 1), gastric outlet obstruction (Figure 2) and colonic stenosis (Figure 3).



Mistakes in chronic diarrhoea and how to avoid them
Chronic diarrhoea is a common condition with a wide variety of possible causes
Chronic diarrhoea, lasting more than 3 or 4 weeks, is a common condition with a wide variety of different possible causes. Estimates suggest 5% of the population have experienced chronic diarrhoea and sought medical advice about it. All gastroenterologists see many patients whose principal complaint is frequent, loose stools, and will be aware of investigations that are needed to diagnose serious conditions such as inflammatory bowel disease (IBD) or colorectal cancer (CRC). Most people who present with chronic diarrhoea will not have these conditions and, if less common disorders are not considered, may be given a diagnosis of diarrhoea-predominant irritable bowel syndrome (IBS-D) or perhaps functional diarrhoea.1 Many different treatments are used for IBS-D and often benefit only a small proportion of patients, leaving many with unmet needs, seeking further investigation, advice and treatment.
Guidelines for the investigation of chronic diarrhoea in adults have recently been updated.2 These guidelines provide recommendations for investigating most patients who have chronic diarrhoea, and reflect the now greater availability of simple tests such as faecal calprotectin, coeliac serology, lower gastrointestinal endoscopy and tests for bile acid diarrhoea (BAD). The criteria for functional gastrointestinal disorders were revised in 2016 (Rome IV), with modifications made to the definitions of the various functional bowel disorders (FBD).1 The revised criteria recognise a continuum between functional diarrhoea and IBS-D, and the usefulness of the Bristol stool form scale (BSFS) types 6 and 7 for defining diarrhoea. Approaches to the clinical evaluation of patients are indicated in those articles,1–2 which provide much of the evidence discussed here, backed up by my clinical experience, highlighting certain mistakes that can be made in the management of chronic diarrhoea.Mistakes in pancreatic cystic neoplasms and how to avoid them
Surveillance and therapeutic approaches need to be tailored appropriately
Pancreatic cystic neoplasms (PCN) are a frequent and clinically challenging condition. PCN prevalence increases with age and reports estimate that they may be present in 2–45% of the general population1,2. In addition, the biological behaviour of the various types of PCN differs (ranging from benign to malignant [table 1]), requiring different surveillance and therapeutic approaches. Correct management of PCN is, therefore, critical for avoiding progression to cancer, but at the same time avoiding unneeded close and long-term follow-up, unnecessary invasive diagnostic procedures and overtreatment.
In this article, we discuss some frequent and relevant mistakes that can be made in the diagnosis, surveillance and management of PCN, and propose strategies to avoid them. These strategies are mainly based on the recently published European evidence-based guidelines on PCN.3

Mistakes in mouse models of NASH and how to avoid them
Several animal models attempt to mirror each stage of human NAFLD
Nonalcoholic fatty liver disease (NAFLD) is a growing cause of chronic liver disease worldwide that can manifest as nonalcoholic fatty liver (NAFL) or nonalcoholic steatohepatitis (NASH). Compared with NAFL, NASH poses a substantially higher risk of progression to advanced liver disease, cirrhosis and hepatocellular carcinoma (HCC). Given the lack of directed pharmacological therapies and the complex, multifactorial disease aetiology and pathology, NAFLD is expected to become the leading cause of end-stage liver disease in the coming decades.
Mistakes in small bowel bleeding and how to avoid them
Definitive management of small bowel bleeding can pose formidable challenges
Over the past 17 years, the disruptive impact of technologies including small bowel capsule endoscopy (SBCE), device-assisted enteroscopy (DAE) and dedicated cross-sectional imaging has transformed the investigation and management of small bowel pathology. Although a small bowel source only accounts for 5–10% of all cases of gastrointestinal bleeding,1–2 definitive management of small bowel bleeding even in the current era of advanced imaging, can still pose formidable challenges.
Mistakes in acute jaundice and how to avoid them
Jaundice—one of the major signs in medicine—can result from numerous conditions
Jaundice or icterus (derived from the ancient Greek word ikteros that described the yellow-breasted oriole bird) is not a diagnosis in itself but constitutes one of the major signs in medicine. Jaundice refers to the yellowish discoloration of tissue that occurs as a consequence of the deposition of bilirubin. This discoloration is a physical manifestation of a marked increase in serum bilirubin levels. Normal serum bilirubin values are <17 μmol/L; for jaundice to be perceived visually serum bilirubin levels need to be elevated to >40 μmol/L (equivalent to 2.5 mg/dL).1
Most serum bilirubin is formed from the breakdown of the haem contained in senescent red blood cells by the reticuloendothelial system. Thus, unconjugated bilirubin is released in the bloodstream, where it is bound by albumin. Through the blood circulation bilirubin is moved to liver hepatocytes, where it undergoes further processing. In brief, bilirubin becomes conjugated in the hepatocytes through glucuronidation, which allows it to be excreted from the body (unconjugated bilirubin is water insoluble and cannot pass into the urine). Conjugated bilirubin forms one of the main components of bile and most of it passes through the biliary tree to the intestine. Unconjugated and conjugated bilirubin are reported in laboratory measurements as indirect and direct bilirubin, according to their chemical properties (i.e. reaction with reagents).1 Jaundice can be caused by abnormalities in any of the steps comprising the formation, metabolism and excretion of bilirubin. In addition, these processes may be functioning properly, but jaundice can be seen because of an obstruction of the biliary tree at any point, from its intrahepatic origins to its end at the ampulla of Vater. For this reason, it is clear that numerous conditions can result in jaundice. When faced with a patient presenting with jaundice a reasonable and careful diagnostic approach is, therefore, warranted to elucidate the underlying cause of this sign. Conventional wisdom may be that “jaundice by itself never killed anyone,” but it is imperative to find the cause as soon as possible, as prompt intervention saves lives in many cases. Here, we outline several of the mistakes made when approaching a patient presenting with acute jaundice based on our clinical experience and published data.Mistakes in capsule endoscopy and how to avoid them
Wireless technology means capsule endoscopy is well tolerated, but it is also a drawback
Capsule endoscopy is a noninvasive technique intended for studying the small bowel and/or colon. The capsule endoscope consists of a small, wireless, pill-sized camera that can be swallowed and allows direct visualization of the gastrointestinal mucosa. The design of the capsule differs depending on the part of the gastrointestinal tract to be studied. The small-bowel capsule has one optical dome and is generally used in patients who have suspected bleeding or to identify evidence of active Crohn’s disease. By contrast, the colon capsule has two optical domes, a higher frame rate and can be considered as an alternative to conventional colonoscopy, especially for cases when the examination was incomplete. There is also a new capsule with two optical domes that is designed for the panendoscopic study of both the small bowel and colon.
The main characteristic of capsule endoscopy is the wireless technology, which enables it to be very well tolerated. However, this feature is also one of its drawbacks, as the capsule cannot be directly controlled by the physician. The capsule moves through the gut depending solely on intestinal motility, and the examiner is not able to drive it back and forth or to stop it to look more carefully at any finding. Moreover, the visualization relies heavily on the adequacy of intestinal cleansing as rinsing with water and aspiration are not possible. Capsule endoscopists should be aware of these shortcomings, as they directly affect the reading and diagnosis. Here we discuss frequent errors that are made when performing capsule endoscopy, based on the published literature and more than 15 years’ experienceMistakes in clinical investigation of gastrointestinal motility & function
Symptoms related to abnormal motility and function are very common.
Symptoms related to abnormal gastrointestinal motility and function can occur from the moment food is swallowed to the time stool is passed into the toilet. A recent UEG survey indicated that dysphagia, heartburn, bloating, abdominal pain and changes to bowel habit are each reported by 5–15% of the general population.1 These symptoms are frequent reasons for seeking medical attention from general physicians and for referral to specialist gastroenterologists. Most patients with these symptoms do not have neoplasia, infection or inflammation on initial investigation, but rather so-called functional gastrointestinal symptoms.2,3
For patients with mild symptoms, negative tests provide reassurance and simple, symptomatic management might be all that is required (e.g. acid suppression, stool regulation). However, for those with severe symptoms that persist on therapy, ruling out life-threatening disease is not sufficient, and referral to the neurogastroenterology and motility (NGM) laboratory for physiological measurements is often indicated.Clinical investigations aim to explain the cause of symptoms and establish a diagnosis that can guide rational treatment. Until recently, it could be argued that manometry, scintigraphy, breath tests and related tests rarely provided this information. As a result, only patients with suspected major motility disorders (e.g. achalasia, severe reflux disease or faecal incontinence) were routinely referred to the NGM laboratory for tests. Technological advances, such as high-resolution manometry (HRM), now provide objective measurements not only of motility, but also of function in terms of the movement (and digestion) of ingested material within the gastrointestinal tract. Furthermore, the ability to associate events (such as bolus retention, reflux or gas production) with symptoms provides an indication of visceral sensitivity and can identify what is causing patient complaints. Here, I discuss frequent mistakes in clinical investigation of gastrointestinal motility and function based on a series of consensus documents published by members of the International Working Group for Disorders of Gastrointestinal Motility and Function.
Mistakes in the endoscopic diagnosis and management of Barrett’s oesophagus and how to avoid them
Barrett’s oesophagus is the precursor to oesophageal adenocarcinoma, which carries a poor prognosis,1 and it is likely that all endoscopists and gastroenterologists will encounter Barrett’s oesophagus in their clinical practice.
Careful assessment and management of patients who have Barrett’s oesophagus with endoscopic surveillance and endoscopic endotherapy aim to reduce the risk of progression to invasive adenocarcinoma. Advances in endoscopic diagnosis and therapy should, therefore, help to reduce the risk of progression. As with all premalignant conditions and surveillance programmes,2 careful multidisciplinary management of the patient is important to reduce the risk of causing them to become unduly concerned. Here, we present some mistakes that in our experience are commonly made in the endoscopic diagnosis and management of Barrett’s oesophagus and give advice on how to avoid them.Mistakes in short bowel and how to avoid them
Short bowel manifests as high stomal output or diarrhoea, dehydration and malnutrition.
Short bowel is a condition that occurs after single or multiple intestinal resections. The incidence of short bowel in Europe is 2 per million of the population1–3 and it carries with it lifelong morbidity and mortality. The initial recognition and management of short bowel in the adult population tends to occur in the postoperative period and in the secondary care setting, where specialist input from clinicians experienced in short bowel is often lacking.
Normal small bowel length is 275–850 cm.4–7 It is accepted that when the length of small bowel is reduced to less than 200 cm it may be insufficient to enable adequate absorption of fluids and micronutrients. The symptoms of short bowel (often referred to in the literature as short bowel syndrome) are secondary to a reduction in intestinal surface area together with an increased motility of the remaining section of small bowel, with accompanying increased secretion into the lumen. These intestinal secretions vary in their electrolyte content and osmolality depending on the anatomical location, with the highest chloride and potassium loss from gastric secretions and high sodium loss from jejunal secretions.8 Clinically, short bowel manifests itself as a high stomal output or diarrhoea, dehydration and malnutrition. High stomal output or diarrhoea do not, however, necessarily equate immediately to short bowel; conversely, a small bowel longer than 200cm may be insufficient if it is diseased. Here, we discuss some of the pitfalls that are encountered in the recognition and management of short bowel and have suggested an algorithm for assessing and managing patients with a high stomal output. Although some of these pitfalls may appear obvious, they are addressed here because they are commonly encountered in clinical practice (summarised in table 1 at the end of the article).Mistakes in paediatric IBD and how to avoid them
Better clinical outcomes are increasingly being sought in young people with IBD
Around 1 in 10 cases of inflammatory bowel disease (IBD) will present before adulthood, with the median age at presentation being 11–12 years.1 IBD in children and young people is associated with more extensive disease, increased disease activity and a higher rate of complications compared with adult-onset IBD.2 Worldwide, estimates of paediatric IBD prevalence rates are lacking, but data suggest its incidence is increasing.3
Risk factors for paediatric IBD include immigration to high prevalence regions, particularly to countries that have Westernised diets, increasing geographical latitude, and European ancestry (versus belonging to an indigenous population).4 The risk may also be higher in children of certain ethnicities (South Asian, Hispanic, and East Asian).5
While the pathophysiology and clinical presentation of paediatric IBD is well understood, the role of genetics and personalised treatment is currently the focus of a significant amount of international research. Better clinical outcomes—including optimal nutrition, improved growth, better quality of life and increased disease remission rates with decreased occurrence of complications—are increasingly being sought in children and young people with IBD.4
This article discusses mistakes commonly made when identifying, diagnosing and managing children whom are suspected or confirmed to have IBD. The mistakes and discussion are based on published evidence where possible, plus our clinical experience of looking after children with IBD.
Mistakes in tissue sampling during endoscopy and how to avoid them
Tissue acquisition is the most common manoeuvre performed during endoscopy.
