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Upper gastrointestinal endoscopy 

Upper gastrointestinal endoscopy

Upper gastrointestinal endoscopy

Adrian R.W. Hatfield

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Flexible fibre optic endoscopes were developed in the mid-1960s, leading to the growth of gastrointestinal endoscopy as we now know it. The recent availability of cheaper, miniaturized colour chips has led to the development of video endoscopes, providing an excellent clear view that does not deteriorate with age (as it does with fibre optic devices). With improvements in software, the endoscopic video image can be magnified: modern instruments will zoom up to 25 × magnification, and mucosal detail can also be enhanced electronically so that small lesions a few millimetres in size can be seen quite clearly. The modern video endoscope image can be instantly printed out and archived digitally on a computer system.

Endoscopy has now become the investigation of choice in patients with retrosternal or upper abdominal symptoms where barium radiology would previously have been employed. The advantages of detecting grades of inflammation and erosive change, rather than radiologically obvious ulceration, are obvious. Equally, the ability to take samples from the gastrointestinal tract with brush cytology or biopsy greatly enhances the diagnostic accuracy, not just in differentiating between benign and malignant ulcers and strictures, but also in assessing degrees of inflammatory change and in detecting dysplasia, e.g. in Barrett’s oesophagus.

Endoscopy is essential in significant gastrointestinal bleeding to identify and—in many cases—treat the cause, with various therapeutic methods possible for erosions, ulcers, and oesophageal varices.

More recent developments in the practice of upper gastrointestinal endoscopy include the use of enteroscopy for direct vision of the jejunum, video capsule endoscopy for diagnosis of obscure bleeding lesions, and an impressively useful range of therapeutic techniques including laser therapy. Endoscopic retrograde cholangiopancreatography (ERCP) is useful for the diagnosis and noninvasive removal of gallstones from the common bile duct.

In a wider perspective, upper gastrointestinal endoscopy has had a driving role in the development of the specialty of gastroenterology as a result of the imaginative application of techniques and applied physics to common medical conditions affecting hitherto inaccessible regions of the abdomen and its hollow viscera.


The external specifications and handling of the new video endoscopes are similar to their earlier fibre optic counterparts and thus the techniques for disinfection and endoscopy are similar for both ranges of equipment. The disadvantage of the modern equipment is that the video endoscopy system needs considerable hardware. In most instances a video monitor, light source, and processor are located in an endoscopy unit and are not so easily moved to a different location such as the intensive therapy unit or operating theatre for emergency endoscopy. In the acutely bleeding patient, the presence of excessive blood in the lumen of the gastrointestinal tract diminishes the efficiency of the video processing so that the image obtained may be unsatisfactory.

The latest type of high-definition endoscope, processor, and monitor can be used for two new techniques, narrow band imaging (NBI) and autofluorescent imaging (AFI). NBI uses the properties of short-wavelength light of two different wavelengths to enhance the visualization of capillaries in the superficial mucosa and vessels deeper in the mucosa. These are seen as two different colours, which enhances the visualization and diagnosis of otherwise poorly identifiable lesions. AFI utilizes the property of short-wave light in the blue area of the spectrum to elicit a green fluorescence from normal mucosa. Thickening of the mucosa by malignant infiltration tends to inhibit this and abnormal tissue may fluoresce less, allowing for endoscopic detection of submucosal abnormality.

Endoscopy units and disinfection techniques

It is now well recognized that the care of the instruments and other equipment, together with the important aspects of patient safety, are greatly improved by having a purpose-built endoscopy unit staffed by experienced endoscopic nursing staff who are trained in handling and disinfecting endoscopes and in patient safety during and after intravenous sedation.

Most endoscopy units have a purpose-built disinfecting machine which can take single or multiple instruments. After suitable mechanical cleaning, a disinfecting agent will be automatically pumped through the channels of the instrument for a given period of time and flushed out afterwards. The choice of disinfecting agent varies between units but the trend has been away from hazardous agents such as glutaraldehyde (Cidex) to less harmful agents, such as Nu-Cidex or Tristel, that do not need sophisticated extraction and ventilation.

For routine, simple diagnostic upper gastrointestinal endoscopy many patients are now routinely endoscoped without sedation, after local anaesthesia to the throat only. ‘No sedation endoscopy’ is suitable for busy units with long lists of day cases. However, large numbers of endoscopies, particularly in apprehensive or sick inpatients and those needing more complicated procedures, are still performed under intravenous sedation.

There are now clear guidelines, such as those drawn up by the British Society of Gastroenterology, for the practice of administering intravenous sedation for endoscopic procedures. Patients are now monitored with pulse oximetry and oxygen is given routinely to ill or elderly patients, and to other patients if oxygen saturation falls during the procedure. The precise choice of sedation varies between units and will depend on the patient and the type of procedure performed; however, diazempam and midazolam remain the two most common sedative agents used, often combined with pethidine for more lengthy or invasive procedures. It is not uncommon to reverse the effect of the benzodiazepine sedation with flumazenil and any opiate sedation with naloxone. On rare occasions general anaesthesia will need to be used for endoscopy, usually for children or adults with ventilatory problems. There is an increasing trend in some countries, but not yet to any major extent in the UK, for complex procedures to be performed under propofol anaesthesia. Specially trained anaesthetic nurses can be trained to administer this.

Specific risk of infection with endoscopy

In the past patients with heart murmurs were routinely given antibiotics to cover endoscopic procedures. It is now recommended that only patients with prosthetic valves need be given routine prophylactic antibiotic cover, with a single parenteral dose of a broad-spectrum penicillin before the procedure.

Current disinfecting agents and schedules will cope with hepatitis B and C and HIV infection. All endoscopic staff wear disposable gloves and the nurse nearest the patient’s mouth will usually wear a visor to cover eyes, nose, and mouth, particularly with a patient of known infective risk. As there is no effective way of sterilizing an endoscope against prions (at present thought to be the transmissible agent in Creutzfeldt–Jakob disease), the current United Kingdom Department of Health guidelines make it clear that all equipment used on patients with suspected Creutzfeldt–Jakob disease should be quarantined afterwards and if the diagnosis were proven at a later date, only used thereafter on patients with Creutzfeldt–Jakob disease. Patients with suspected Creutzfeldt–Jakob disease should therefore not be endoscoped and alternative ways of diagnosis or treatment should be sought.

Diagnostic endoscopy in the gastrointestinal tract

In recent years, it has become routine to take gastric biopsies in patients with peptic problems to detect the presence of Helicobacter pylori. The routine use of a simple CLO test, where mucosal biopsies are inserted into a gelatin well containing a colouring agent that turns yellow to red in the presence of helicobacter urease, will be satisfactory. In some patients with infection resistant to multiple eradication therapies, gastric biopsies are necessary in this situation for culturing the bacteria to ascertain sensitivity. In younger patients where malignant disease is less of a concern, serum, faecal, or breath test analysis is an acceptable alternative to establishing helicobacter infection and thus such patients could be treated initially without endoscopy and gastric biopsy.

Most gastric cancers in the United Kingdom are diagnosed when the patient is symptomatic and thus the finding of a mucosal cancer is rare. Most lesions are straightforward to diagnose endoscopically and biopsies are usually confirmatory. Cancers that infiltrate the wall of the stomach below the mucosa are difficult to diagnose endoscopically as endoscopic biopsies are usually quite superficial. In this situation a ‘double punch’ type technique is useful, where a second biopsy is taken from the deeper submucosa through the small defect of the first biopsy. Linitis plastica is difficult to assess endoscopically, particularly where anticholinergic and other agents may have been used routinely to inhibit peristalsis at the start of the endoscopy. In such patients, a barium meal may help in the diagnosis by showing the lack of gastric motility.

Small bowel endoscopy (enteroscopy)

For many years, routine upper gastrointestinal endoscopes were not of sufficient length to pass beyond the duodenojejunal flexure into the small bowel. Enteroscopes are now made that can be advanced under direct vision down the upper small intestine or, alternatively, a thinner endoscope is allowed to pass down the small bowel spontaneously with the help of an inflated balloon and then the bowel lumen is visualized on withdrawal. Such endoscopic procedures are lengthy and difficult and will not necessarily view the entire small bowel. A more comprehensive view is sometimes obtained, particularly in the hunt for obscure bleeding lesions, by passing a standard upper gastrointestinal endoscope up and down the small intestine through small enterotomies at the time of laparotomy, with a surgeon concertina-ing the small bowel over the shaft of the endoscope.

The rather lengthy, tedious, and unpredictable techniques of small bowel biopsy using a Crosby capsule have been completely superseded by routine upper gastrointestinal endoscopy with biopsies from the distal duodenum. Such biopsies have been shown to be very representative of the upper jejunal mucosa. This technique is now used routinely in the diagnosis of coeliac disease.

Video capsule endoscopy of the small bowel

Over the last few years a new technique of visualizing the small intestine has been developed and, although expensive, is readily available. A small capsule containing a minute camera and transmitter can be swallowed by the patient or released at the time of endoscopy. Providing the small intestine has been cleared with a colonoscopy-type bowel preparation, the capsule transmits individual images of amazing clarity every 0.5 s to a receiver strapped on the abdomen. The capsule takes about 4 h to pass down the small intestine.

This technique is particularly useful in the detection of superficial mucosal lesions, such as angiodysplasia in difficult gastrointestinal bleeding or early Crohn’s disease, that might otherwise be undetected by x-ray examination using barium contrast.

Therapeutic endoscopy in the upper gastrointestinal tract

Over the last 20 years, a wide range of therapeutic manoeuvres have been developed for use in various situations in the upper gastrointestinal tract.

Gastrointestinal bleeding

Oesophageal varices can be injected through the mucosa with ethanolamine oleate under direct vision. Paravasal injection is best avoided as it can lead to secondary bleeding from mucosal ulceration and sometimes later oesophageal stricture formation. Endoscopic sclerotherapy can be repeated at weekly or monthly intervals until the varices have been obliterated. Bleeding gastric varices can also be injected, but these are more difficult to obliterate. More recently, endoscopic banding techniques have been employed, both in the acutely bleeding patient and the chronic situation. Single or multiple bands could be put on varices in the oesophagus or, sometimes, in the fundus of the stomach. The addition of thrombin into gastric varices after banding may enhance successful eradication and reduce the risk of bleeding if the bands slip off too early.

Bleeding erosions and ulcers can be injected with dilute adrenaline (1:10 000). This may be satisfactorily in reducing bleeding in the short term and can always be repeated if necessary. A similar effect can be obtained by the use of multicontact diathermy probes or heater probes. Bleeding vascular abnormalities, such as angiodysplasia, can be treated with thermal probes but more satisfactorily with noncontact laser which does not pull off a coagulum and has the extra benefit of destroying vessels just below the mucosa.

More recently argon photocoagulation (APC) has become available. A diathermy current in a beam of argon gas provides a safe and predictable way of coagulation without direct contact with the mucosa. Although more costly, it is more effective than simple touch diathermy devices and a very reasonable alternative to thermal laser coagulation.

Benign oesophageal strictures

Commonly, a peptic stricture above a hiatus hernia secondary to reflux will produce dysphagia but benign strictures due to other causes, such the swallowing of corrosive substances and postsurgical anastomotic strictures, can be treated by the same endoscopic techniques. In the past, bougies of increasing size were passed over a previously endoscopically placed guide wire and the stricture slowly dilated. More recently, high-pressure dilating balloon catheters, passed over the wire under radiological screening or directly through the scope under direct endoscopic vision, have been used. These are useful for short strictures, but there is still a place for over the wire bougies in very long strictures.

Achalasia of the cardia can be treated with balloon dilatation using a larger balloon of 30 to 40 mm diameter, where the aim is to rupture muscle fibres to weaken the circular muscle sphincter. Alternatively, botulinum toxin can be injected through the mucosa into the muscle sphincter circumferentially at the time of endoscopy. The improvement in swallowing after this procedure is limited and may need to be repeated every 6 months.

Malignant gastro-oesophageal strictures

Most patients with nonoperable tumours of the stomach or oesophagus producing dysphagia are palliated by the insertion of some sort of oesophageal stent. The older silicon rubber prostheses have been replaced by self-expanding metal stents which can be very easily and safely placed through a malignant stricture, often without the need for prior dilatation, thus reducing the risk of perforation. Most of these stents now have a membrane to prevent tumour ingrowth through the mesh but this will sometimes occur at one or either end. Such tumour overgrowth can be treated with endoscopic laser therapy. Brachytherapy can be given via an endoscopically sited tube through the stricture before or after stenting.

Postoperative anastamotic strictures after oesophagogastric resection, sometimes associated with a leak, can now be managed with membrane-covered self-expanding metal stents. The newer stents are potentially removable a few months later when the stricture and leak have sealed.

Removal of foreign objects

Most solid objects such as marbles, rings, and coins should pass spontaneously. The need for removing foreign bodies is usually because they are sharp and may cause damage if left in situ. Most objects can be snared or trapped in a basket and removed intact. Sharp objects can be pulled into a endoscopic overtube to protect the oesophagus from damage during removal.

Polyps and mucosal cancers

Most gastric polyps are entirely benign and do not need removing. Leiomyomas of the stomach or duodenum can be watched if small, but if ore than 5 cm in size should probably be removed.

Endoscopic mucosal resection (EMR)

Patients with larger mucosal tumours usually used to undergo open surgery but newer endoscopic techniques using submucosal resection can tackle lesions that do not infiltrate beyond the submucosa. Careful prior assessment with endoscopic ultrasound is usually needed to make sure that a small tumour can be technically removed in this way. Lesions can be elevated by the submucosal injection of saline and then removed intact or piecemeal, like polyps in the colon. This can be done for small mucosal cancers or dysplasic lesions in Barrett’s oesophagus or similar lesions of the stomach, duodenum, or ampulla of Vater. Newer accessories with a suction cap and banding device, similar to that used with varices, allow the mucosal lesion to be trapped and removed with a snare without damage to the muscle layer and therefore without risk of perforation.

Laser therapy

Thermal coagulation with a YAG laser via a fibre under direct endoscopic vision has been used for many years as a complex but highly effective way of recanalizing tumour obstruction in the oesophagus, stomach, and colon. It is used less now with the widespread development of self-expanding metal stents to relieve luminal tumour obstruction.

Photodynamic laser therapy (PDT) has gained increasing popularity as the lasers used are considerably smaller and cheaper than those used for thermal coagulation. It is also easier to use and safer, and the fibre can be in contact with tissue. The technique is currently used in head and neck, oesophageal, and biliary tumours. After the administration of a photosensitizing drug, such as porfimer sodium, a low-power laser light can be passed down a diffuser fibre which can be endoscopically and radiologically positioned, sometimes inside a balloon to keep it centralized, particularly in the oesophagus, where it is also used for treating high-grade dysplasia in Barrett’s oesophagus. An alternative to PDT in the latter situation is a radiofrequency (RF) probe that can be placed on the surface of an oesophageal balloon or clipped on the end of an endoscope.

Assisted nutrition

There are now many types of enteral feeding tube that can be sited in the upper gastrointestinal tract. Although most fine-bore feeding tubes can be passed on the ward or under radiological control, the prior passage into the stomach of an endoscopic guide wire that is then rerouted through the nose can allow feeding tubes to be positioned accurately, often through an oesophageal stricture or difficult anastomosis, or positioned in the duodenum in patients with gastric stasis. The endoscopic positioning of a nasojejunal feeding tube, beyond the duodenojejunal flexure, is now becoming a common alternative to intravenous feeding in patients with complicated pancreatitis where ‘pancreatic rest’ is needed.

Techniques for placing a gastrostomy tube endoscopically (percutaneous endoscopic gastrostomy, PEG) are now simple and straightforward. After transabdominal puncture into a distended stomach under direct endoscopic vision, a PEG tube with diameter from 8FG to 24FG can be pulled back down the oesophagus through the stomach and a flange, balloon, or button will allow the tube to be anchored firmly up against the gastric mucosa. In patients where there is gastric stasis or in pancreatitis a small jejunal extension tube can be inserted through the PEG tube and positioned endoscopically into the distal duodenum or beyond the duodenojejunal flexure (PEJ).

Endoscopic ultrasound

Special endoscopes are available with a dual capability of endoscopic and ultrasound imaging. Either a rotating or a fixed linear array transducer will provide an ultrasound image at a point where the endoscopist can accurately direct the probe in the lumen of the oesophagus, stomach, or duodenum. Although CT scanning will stage most larger tumours of the upper gastrointestinal tract, pancreas, and bile duct, endoscopic ultrasonography is particularly useful in staging small tumours and particularly mucosal tumours. The linear array ultrasound endoscope can be used for needle biopsy of tumours in the wall of the gastrointestinal tract or head of pancreas and sometimes lymph nodes, either adjacent to stomach, duodenum and increasingly in the mediastinum, through the oesophagus.

There is an increasing use of endoscopic ultrasonography in therapeutic procedures such as coeliac plexus block and endoscopic drainage of pancreatic pseudocysts.

Endoscopy and disorders of the pancreas and biliary tree

Diagnostic endoscopic retrograde cholangiopancreatography (ERCP)

The development of side-viewing duodenoscopes in the 1970s allowed endoscopic visualization of the papilla of Vater and cannulation of the pancreatic and biliary duct systems, endoscopic retrograde cholangiopancreatography (ERCP). For many years ERCP was the gold standard for investigating pancreatic and biliary disorders but, with the advent of CT and MRI scanning, the need for diagnostic ERCP has diminished. ERCP is still extremely useful in the diagnosis of patients with gallstones, sclerosing cholangitis, and biliary tumours where scanning is normal or equivocal, in the absence of overt jaundice. A tissue diagnosis can be obtained with brush cytology and endoscopic biopsy within the bile duct, avoiding the need for percutaneous biopsy.

Diagnostic ERCP is still useful in the assessment of patients with pancreatitis, congenital abnormalities, such as pancreas divisum, and in some patients with a pancreatic mass on scanning where the diagnosis is not clear. Most patients with a carcinoma of the pancreas will present with obstructive jaundice and will need a therapeutic procedure; others without jaundice will usually be diagnosed on ultrasound or CT scanning.

In specialized centres, biliary and pancreatic manometry is performed to assess patients with pancreatobiliary pain with no apparent structural abnormalities. At ERCP, a perfused catheter can be inserted into the bile duct and into the pancreatic duct and pull-through manometry performed. This will show whether elevated basal and peak pressures indicate dysfunction of the sphincter of Oddi.

Therapeutic ERCP


The endoscopic removal of common bile duct stones at the time of ERCP is the treatment of choice for patients presenting with pain, abnormal liver function tests, jaundice, or cholangitis. Following previous cholecystectomy, about 10% of patients will ultimately represent with bile duct stones and endoscopic management is far safer than further surgical exploration of the bile duct. Before laparoscopic cholecystectomy, it is particularly important to investigate and to endoscopically clear the bile duct of stones, if suspected. Failure to do so may increase the likelihood of postoperative bile duct leaks. At the time of ERCP if stones are located in the biliary tree, a small diathermy cut is made into the bile duct through the papilla and, through the sphincterotomy, stones can be extracted with a balloon or basket. If the stones are too numerous or too large to extract at the first procedure, small pigtail stents are inserted into the bile duct to guarantee good drainage without stone impaction and therefore reduce the incidence of postprocedure cholangitis.

Most large stones can ultimately be removed using a mechanical crushing basket (lithotripter) or sometimes with the help of extracorporeal shock wave lithotripsy, following which fragments can be removed from the bile duct at follow-up ERCP. In experienced hands, the technical failure rate is low and thus the need for surgical reintervention is uncommon. Only in patients with very large bile duct stones, intrahepatic stones, or stones above biliary strictures is there a need for further procedures, such as intraduct choledochoscopy, using small endoscopes passed directly into the bile duct, with direct contact lithotripsy using a pulse dye laser or an electrohydraulic probe. Very elderly or frail patients with large bile duct stones can be managed long-term by simple placement of an endoscopic stent beside the stones for drainage to prevent jaundice and/or cholangitis. Such stents can be changed over the years as necessary.

Benign strictures

Postoperative anastamotic strictures or those following bile duct damage at the time of cholecystectomy can initially be managed with intermittent biliary balloon dilatation at the time of ERCP or simple endoscopic stent placement. In the young patient, after a trial of dilatation or stenting for a reasonable length of time, surgical reconstruction of the bile duct might be needed if it is clear that endoscopic treatment is not leading to resolution of the stricture. In patients with primary sclerosing cholangitis, there may be single or multiple strictures in the intrahepatic and extrahepatic biliary tree, often in association with pigment stones, which can be difficult to dilate or stent. A variable proportion (5–20%) of patients with primary sclerosing cholangitis develop a cholangiocarcinoma and this can be very difficult to prove even with good ERCP, biliary cytology, CT, and MR scanning.

Malignant bile duct obstruction

Pancreatic and bile duct cancer and carcinoma of the ampulla of Vater can all produce stricturing of the biliary tree at different levels. At ERCP the stricture can be dilated and then an endoscopic 10FG polyethylene stent placed to relieve jaundice. These stents are cheap and usually stay patent for 4 to 5 months. In pancreatic cancer, about one-third of patients will survive long enough to occlude their stent, in which case a further procedure is performed to remove the blocked stent and replace it with a new one. Self-expanding metal stents offer a way of palliating patients for longer as they have a lumen of 10 mm which gives excellent long-term drainage. At present, biliary metal stents have an open mesh and tumour infiltration may occur, causing recurrent jaundice and/or sepsis. In that situation, a plastic stent can be inserted through the blocked metal stent to achieve drainage. Membrane-covered metal stents are now available which should result in long term patency and, hopefully, avoid the problem of tumour ingrowth.

In some patients with cholangiocarcinoma at the hilum of the liver, separate obstruction to right and left main ducts or subsegments may be found. In such a situation, more than one stent may be necessary to relieve jaundice or sepsis. Brachytherapy for cholangiocarcinoma can be administered endoscopically using an iridium wire source inserted down an endoscopically placed catheter inside the stent within the cholangiocarcinoma. Photodynamic therapy can also be administered using a diffuser laser fibre, endoscopically sited within the malignant biliary stricture(s).


In patients with acute, relapsing, and chronic pancreatitis a variety of endoscopic therapies can be performed. After pancreatic sphincterotomy, stones can be removed from the pancreatic duct, strictures can be stented, and drainage of the dorsal duct in pancreas divisum can be achieved. Peripancreatic fluid collections and pseudocysts can also be managed by pancreatic duct drainage or direct endoscopic cyst puncture and stenting techniques. Pancreatic endotherapy is difficult and can be associated with complications. Nevertheless, in selected patients it may be very valuable and could avoid difficult and complex pancreatic surgery.

Gastric outlet obstruction

About 10% of patients with pancreatobiliary tumours will develop gastric outlet obstruction as a late complication as tumour infiltrates the duodenum. Conventionally, a surgical gastric bypass has been unavoidable and this has carried a substantial morbidity/mortality as these patients are often very frail in the latter stages of their malignant disease. A large-diameter self-expanding metal ‘enteral’ stent can now be placed in the stomach and duodenum at the time of endoscopy. This rapidly relieves symptoms of gastric outlet obstruction and allows the patients to eat a reasonable diet without vomiting, thus avoiding the need for bypass surgery.

Hazards and complications

Diagnostic endoscopy carries very few risks. With careful attention to nursing techniques and sedation protocol, cardiovascular problems during endoscopy and aspiration pneumonia after it are extremely rare. Direct damage to the upper gastrointestinal tract during insertion and subsequent inspection down to the duodenum is extremely unusual but rarely the cricopharynx, lower oesophagus above the cardia, and duodenal cap are sites of direct perforation with the endoscope, more commonly with inexperienced endoscopists. An unrecognized pharyngeal pouch represents a real hazard during insertion of the endoscope and might lead to a perforation if undue force is applied.

Most complications of endoscopy occur during therapeutic procedures and are specific to the type of procedure being performed.

  • The perforation rate following oesophageal dilatation is extremely low now that techniques and equipment have improved. The development of self-expanding stents in the oesophagus avoids the need for forceful dilatation of malignant strictures and this has radically lowered the postprocedure complication rate of perforation. Due to the size of the balloon used in dilating achalasia of the cardia, perforations can be seen. Anyone who develops pain or discomfort after oesophageal dilatation should be assumed to have developed perforation, a chest radiograph should be obtained and if there is evidence of mediastinal air or surgical emphysema, conservative management with nil by mouth, parenteral antibiotics, and intravenous feeding is advocated. Many patients will settle conservatively without the need for surgical intervention.

  • The complications of ERCP are well known and more frequent than those of other endoscopic manoeuvres in the upper gastrointestinal tract. Even with diagnostic ERCP, up to 2% of patients may develop postprocedure pancreatitis after either manipulation at the papilla or the injection of contrast into the pancreas. Such pancreatitis is usually self-limiting and mild. Some patients may have a very elevated amylase in the absence of pancreatitis or pain. After endoscopic sphincterotomy and any therapeutic manoeuvre in the pancreatic or biliary tree, pancreatitis and bleeding can occur. Between 2 and 5% of patients may have some degree of bleeding, but only a small proportion of these will need a blood transfusion or, rarely, surgical intervention. There is also a small risk of retroperitoneal leakage and perforation after sphincterotomy. With the use of periprocedure antibiotics and the routine use of biliary stents after incomplete gallstone clearance within the bile duct, the incidence of postprocedure cholangitis is minimal.