Enteroscopy: Small Bowel Endoscopy ?What It Shows, What It Misses

Key takeaways

• Enteroscopy both looks and treats, biopsies, bleeding control and polyp removal are possible in the same session.
• Enteroscopy rarely covers the entire small bowel; segments can remain unexamined.
• A normal enteroscopy does not exclude small bowel disease, especially if only part of the bowel was reached.
• Capsule endoscopy sees the small bowel but cannot biopsy or treat; the two tests answer different questions.
• Sedation or anaesthesia is usual, so a responsible adult should accompany the patient home.

At a glance

Also known as

• Small bowel endoscopy
• Deep enteroscopy, balloon enteroscopy, DBE / SBE
• Double balloon endoscopy, "DBE test"
• Commonly said in Indian clinics as "small intestine endoscopy" or "chhoti aant ki endoscopy"

What enteroscopy is

The small intestine is several metres long, freely mobile and looped, which is why a standard gastroscopy reaches only the first part of the duodenum and a colonoscopy usually only the last few centimetres of the ileum. Enteroscopy uses a longer scope, and in balloon-assisted techniques an overtube with inflatable balloons, to pleat the bowel over the scope and advance much deeper.

Types of enteroscopy

• Push enteroscopy: a long scope advanced through the mouth, reaching the proximal jejunum. Quicker, but limited depth.
• Single-balloon enteroscopy (SBE): one balloon on the overtube anchors the bowel while the scope advances.
• Double-balloon enteroscopy (DBE): balloons on both scope and overtube; generally allows the deepest insertion and is often preferred when extensive therapy is planned.
• Spiral or motorised spiral enteroscopy: a rotating overtube pleats the bowel. Availability has changed over time and this technique is not offered everywhere.
• Intraoperative enteroscopy: the scope is guided by the surgeon during an operation when other approaches have failed.

Retrograde (anal route) enteroscopy is used when the suspected lesion is in the distal small bowel. Sometimes both routes are used on separate days to examine the whole small intestine.

Why enteroscopy is done

• Small bowel bleeding: the commonest reason, iron-deficiency anaemia or overt bleeding with a normal gastroscopy and colonoscopy. Angioectasias, ulcers and Dieulafoy lesions can be treated at the same sitting.
• Abnormal capsule endoscopy or CT/MR enterography: to reach, biopsy or treat a lesion already suspected on imaging.
• Suspected or known Crohn's disease: to sample deep small bowel inflammation or dilate a short stricture.
• Coeliac disease that is not responding: to look for refractory disease, ulcerative jejunitis or lymphoma.
• Suspected small bowel tumours, polyps and polyposis syndromes: including Peutz-Jeghers polyp removal.
• Chronic diarrhoea or malabsorption of unclear cause after simpler tests.
• Foreign body or retained capsule retrieval.
• Altered anatomy: reaching the bile duct or a surgically bypassed stomach after Roux-en-Y or Billroth II surgery.

Who should consider enteroscopy

• Adults with iron-deficiency anaemia or gastrointestinal bleeding where upper endoscopy and colonoscopy have not explained the blood loss.
• People with an abnormality seen on capsule endoscopy or cross-sectional enterography that needs tissue diagnosis or treatment.
• People with known Crohn's disease where the extent or nature of small bowel disease will change treatment.
• People with coeliac disease whose symptoms persist despite a strict gluten-free diet.
• Families with inherited polyposis syndromes needing small bowel polyp clearance.

Enteroscopy is not a screening test and is not a first-line investigation for common indigestion, bloating or uncomplicated abdominal pain. The decision rests with a gastroenterologist who has reviewed the full clinical picture.

What enteroscopy cannot detect or exclude

• It usually does not see the whole small bowel. Depth of insertion varies with technique, anatomy, adhesions and operator experience. A "normal" study may simply mean the abnormal segment was never reached.
• It cannot exclude small bowel bleeding. Angioectasias bleed intermittently and may look unremarkable between bleeds. Recurrent bleeding after a normal enteroscopy is well recognised and needs re-assessment, not reassurance.
• It sees only the mucosal surface. Lesions in the bowel wall, mesentery, or outside the bowel, including some tumours such as GISTs that grow outwards, can be missed. CT or MR enterography is better for extramural and mesenteric disease.
• It does not assess bowel motility or transit as a whole.
• Biopsies sample only tiny areas. Patchy disease can be missed, and a negative biopsy does not exclude the suspected condition.
• It cannot tell how well the bowel absorbs nutrients: that needs blood tests and clinical assessment.
• A negative result is "nothing seen in the segments examined", not "nothing wrong". If symptoms, bleeding or anaemia continue after a normal enteroscopy, return to your doctor.

Related but different examinations

These tests are not ranked from worst to best. Which comes first depends on the problem. For overt small bowel bleeding, capsule endoscopy often comes first to localise the lesion, but if there is suspected obstruction or stricture, enterography is done first because a capsule could become stuck. In brisk active bleeding, CT angiography or direct enteroscopy may be chosen instead. In suspected small bowel Crohn's disease, MR enterography is often the initial test.

How to prepare

Preparation is set by the endoscopy unit performing the procedure, and the written instructions given by that unit take precedence over anything read online.

• Fasting: commonly no solid food from the previous night, with clear fluids stopped a few hours before. Exact timings differ between units and with the planned anaesthesia.
• Bowel preparation: required for the retrograde (anal) route and sometimes for deep antegrade studies. Purgative type and volume vary by unit.
• Medicines: bring a full list, including blood thinners, antiplatelets, insulin and other diabetes medicines, iron tablets, and any AYUSH, herbal or gym supplements. Do not stop or change any prescribed medicine on your own, the prescriber and the endoscopist decide together.
• Escort and travel: sedation means you must not drive or travel alone afterwards.
• Tell the team about: heart or lung disease, sleep apnoea, previous abdominal or bariatric surgery, adhesions, known strictures, pregnancy, implanted devices, allergies and previous sedation problems.

Diabetes on glucose-lowering treatment

Fasting plus purgatives can cause hypoglycaemia. Ask the prescriber in advance how to handle insulin, sulfonylureas and SGLT2 inhibitors, and request an early slot. Carry glucose for use if advised.

Chronic kidney disease, heart failure or fluid restriction

Large-volume bowel preparation and high fluid intake can be unsafe with advanced CKD or heart failure. The regimen and volumes must be individualised by your treating doctor; do not follow generic purgative instructions.

Pregnancy

Enteroscopy in pregnancy is uncommon and reserved for urgent indications, with obstetric and anaesthetic input on sedation and positioning.

Children

Paediatric enteroscopy uses smaller scopes, weight-based preparation and usually general anaesthesia, and is performed in centres with paediatric gastroenterology support.

Older adults and frailty

Sedation risk, dehydration from purgatives and cardiac reserve need review before booking; a modified preparation is often used.

What happens during enteroscopy

• Before: consent, a check of fasting and medicines, an intravenous line, and monitoring of pulse, blood pressure and oxygen saturation.
• Sedation: conscious sedation for shorter studies; general anaesthesia or deep sedation is common for prolonged deep enteroscopy, especially by the oral route.
• Insertion: the scope is passed through the mouth or the anus. Carbon dioxide is usually used to distend the bowel as it is absorbed faster than air and causes less bloating.
• Advancement: in balloon-assisted techniques the balloons inflate and deflate in cycles while the scope and overtube are advanced and the bowel is shortened over them. X-ray screening is used in some units to judge depth.
• Findings and therapy: biopsies, argon plasma coagulation or clipping for bleeding vessels, balloon dilatation of short strictures, polyp removal or tattooing to mark a site for surgery.
• Withdrawal: the mucosa is re-inspected as the scope comes back, and the deepest point reached is recorded.

How long the procedure takes

• Push enteroscopy: often about 20-45 minutes.
• Balloon-assisted deep enteroscopy: commonly 1-2 hours, longer if extensive therapy is needed or insertion is difficult.
• Recovery: usually a few hours of observation until sedation wears off; total hospital time for a day-care case is often half a day.
• Reports: the endoscopy findings are usually explained on the same day. Biopsy results come later, and the time depends on the laboratory.

Understanding your report

An enteroscopy report describes the route used, how deep the scope reached, what was seen in that territory, what was sampled and what treatment was given. It is a description, not a diagnosis. Interpretation belongs to the gastroenterologist who requested the procedure, in the context of your symptoms, blood tests and imaging.

• "Normal mucosa up to X cm beyond the pylorus/ileocaecal valve": nothing abnormal was seen in the part examined. Bowel beyond that point was not assessed.
• Angioectasia: fragile dilated vessels, a frequent cause of iron-deficiency anaemia, often treatable during the procedure but prone to recurrence.
• Ulcers or erosions: may relate to NSAIDs, Crohn's disease, infection including intestinal tuberculosis, or ischaemia. Biopsy and clinical context decide.
• Villous atrophy or scalloped folds: can suggest coeliac disease or other causes; needs correlation with serology and histology.
• Stricture: a narrowing that may be inflammatory, post-surgical, drug-related, tubercular or malignant.
• Polyp or mass: nature depends on histology, not appearance.

Results vary depending on individual clinical circumstances.

When results can be misleading

Findings that may be missed or falsely reported as normal

• Shallow insertion depth, the lesion lies beyond where the scope reached.
• Poor bowel preparation, retained food, blood clots or bile obscuring the mucosa.
• Intermittently bleeding vascular lesions that appear inconspicuous when not bleeding.
• Lesions hidden behind folds or at flexures, and submucosal or extramural tumours.
• Patchy disease sampled at the wrong site, giving a negative biopsy.

Findings that may be over-called

• Scope trauma, suction artefact and balloon pressure can create redness, petechiae or small erosions that look like disease.
• Mucosal changes near an overtube balloon may mimic inflammation.
• Lymphoid hyperplasia, especially in children, can be mistaken for pathology.
• Recent NSAID use can produce ulcers that are easily attributed to Crohn's disease.

Localisation errors

Depth estimates in the small bowel are approximate. A lesion described as "mid-jejunum" may sit some distance from that point, which matters if surgery is planned, hence tattooing or clipping to mark the site.

Risks and safety

Enteroscopy is generally well tolerated, but it is an invasive procedure with real, if uncommon, risks. Risk is not uniform across the family of techniques, and rises when therapy such as dilatation or polypectomy is performed.

Push enteroscopy

Risks resemble those of gastroscopy: sore throat, transient bloating, sedation effects, and rarely bleeding or perforation. Mucosal stripping of the oesophagus from overtube use has been reported.

Balloon-assisted enteroscopy (single and double balloon)

Added risks include perforation, higher with dilatation of strictures, in altered surgical anatomy and in inflamed bowel, bleeding after therapy, and pancreatitis, which is described particularly with the antegrade route and appears related to overtube and balloon effects. Prolonged sedation carries cardiorespiratory risk. Abdominal pain and distension for a day or so are common and usually settle.

Motorised or spiral enteroscopy

Serious oesophageal and small bowel injury has been reported with motorised spiral devices, which is why availability and use have become restricted. Ask your endoscopist which technique is planned and why.

Intraoperative enteroscopy

Carries the risks of the operation itself in addition to endoscopic risks.

Capsule endoscopy, for comparison

No sedation is needed, but the capsule can be retained in a stricture and may then require enteroscopic or surgical retrieval.

Special situations

Pregnancy

Performed only for pressing indications, with obstetric input, avoiding fluoroscopy where possible and using the minimum effective sedation.

Children

Used for obscure bleeding, polyposis syndromes and Crohn's disease, in paediatric-capable units under general anaesthesia.

Older adults

Cardiorespiratory assessment before sedation matters more than age alone. Preparation is often modified to reduce dehydration.

Diabetes on glucose-lowering therapy

Fasting and purgatives disturb glucose control. Dose adjustment must be planned by the prescriber before the appointment.

Chronic kidney disease

Purgative choice matters; some preparations risk electrolyte disturbance. Regimen must be individualised.

Heart failure or fluid restriction

Volume of preparation fluid needs explicit medical guidance rather than a standard protocol.

People on anticoagulants or antiplatelets

Whether and when to interrupt these depends on the reason they were prescribed and on the planned therapy. Only the prescriber, with the endoscopist, should make that decision.

Altered surgical anatomy

After gastric bypass or Billroth II surgery, enteroscopy is often the only way to reach the excluded stomach or bile duct, but perforation risk is higher and the procedure should be done by an experienced team.

Enteroscopy in the Indian context

• Intestinal tuberculosis is a major consideration. Small bowel ulcers and strictures in India may be tubercular rather than Crohn's disease. The two look similar endoscopically, and enteroscopic biopsy for histology, AFB and molecular testing can be decisive. Misclassification has serious treatment consequences in both directions.
• Anaemia has many overlapping causes. Iron deficiency from diet, hookworm and other parasitic infestation, and haemoglobinopathies such as thalassaemia trait are common. Not all iron-deficiency anaemia needs enteroscopy, the decision follows a careful assessment of bleeding evidence.
• Drug-related small bowel injury. NSAIDs are widely available over the counter; anti-tubercular therapy, and some AYUSH, herbal and gym supplements can affect the gut and liver. Disclose everything you take.
• Availability. Balloon-assisted enteroscopy and capsule endoscopy are concentrated in tertiary centres and metros, so referral and travel are often involved.
• Data protection. Endoscopy images, videos and reports are personal health data, handled under the Digital Personal Data Protection Act 2023.

Cost and insurance in India

Charges for enteroscopy vary widely between cities, between government and private set-ups, and between diagnostic-only and therapeutic procedures. Rather than quoting a figure, ask for a written estimate that itemises each component.

What drives the cost

• Technique: push enteroscopy costs less than balloon-assisted deep enteroscopy.
• Anaesthesia: monitored anaesthesia care or general anaesthesia adds anaesthetist and drug charges.
• Therapy performed: clips, argon plasma coagulation, dilatation balloons, snares and retrieval devices are billed as consumables.
• Histopathology: billed per specimen block; special stains and molecular tests for tuberculosis add cost.
• Setting: day care versus overnight admission, room category, and city.
• Imaging: fluoroscopy use, or a preceding capsule endoscopy or enterography.

Insurance

Enteroscopy done as an inpatient or day-care procedure is often covered by health insurance, since day-care endoscopic procedures are generally recognised. Purely outpatient diagnostic work may not be. Cashless approval usually needs a pre-authorisation with the clinical indication. Waiting periods, sub-limits and pre-existing disease clauses apply as per your policy, so confirm with your insurer or the hospital's insurance desk before the date.

Myths and facts

Frequently asked questions

Is enteroscopy the same as endoscopy?

Enteroscopy is a form of endoscopy, but it targets the small intestine specifically. A routine upper endoscopy examines the oesophagus, stomach and the first part of the duodenum only. Enteroscopy uses a longer scope, often with balloon assistance, to reach the jejunum and ileum where standard scopes cannot go.

Which is better, capsule endoscopy or enteroscopy?

Neither is universally better; they answer different questions. Capsule endoscopy is a comfortable way to survey the small bowel mucosa and localise a problem, but takes no biopsies. Enteroscopy is longer and needs sedation, yet allows sampling and treatment. They are often used in sequence rather than as alternatives.

How deep can the scope actually reach?

Insertion depth is variable and depends on technique, previous abdominal surgery, adhesions, bowel looping and operator experience. Double-balloon enteroscopy generally reaches deepest. Your report should state how far the scope travelled, which tells your doctor how much of the small bowel remains unexamined.

Do I need general anaesthesia?

Not always. Shorter push enteroscopy is often done under conscious sedation. Prolonged deep enteroscopy, particularly by the oral route, is frequently performed under deep sedation or general anaesthesia for comfort and airway safety. The anaesthetist decides after reviewing your heart, lung and airway status.

When can I eat and return to work?

Most people resume light food once sedation has worn off and swallowing feels normal, guided by the unit's advice. If polyps were removed or a stricture dilated, diet restrictions may last longer. Avoid driving, machinery and important decisions for the rest of the day after sedation.

How soon will I get my results?

The endoscopist usually describes what was seen on the same day, once you are awake. Biopsy reports take longer, and tests for tuberculosis or specialised stains add further time. Book a follow-up consultation, because the findings need interpreting alongside your symptoms and blood tests.

Can enteroscopy stop bleeding permanently?

Enteroscopic treatment can stop active bleeding and often improves anaemia. It is not a guaranteed permanent solution, since vascular lesions such as angioectasias may recur or appear elsewhere. Some people need repeat procedures, iron replacement or additional medical treatment. Results vary depending on individual clinical circumstances.

Is enteroscopy safe if I have had abdominal surgery?

Previous surgery and adhesions make the procedure technically harder and increase perforation risk, but enteroscopy is still performed when needed, sometimes it is the only route to a bypassed stomach or bile duct. Tell your team about every previous operation so the approach and consent can reflect the added risk.

Can children have enteroscopy?

Yes, for selected problems such as obscure bleeding, polyposis syndromes or small bowel Crohn's disease. Paediatric enteroscopy uses smaller instruments, weight-adjusted bowel preparation and usually general anaesthesia, and is best done in centres with paediatric gastroenterology and anaesthesia experience.

Sources

• American Gastroenterological Association and American College of Gastroenterology clinical guidelines on the evaluation and management of small bowel bleeding.
• European Society of Gastrointestinal Endoscopy (ESGE) guidelines on small bowel capsule endoscopy and device-assisted enteroscopy, including the ESGE position on motorised spiral enteroscopy.
• ESGE and ASGE guidance on periprocedural management of antithrombotic agents and on sedation in gastrointestinal endoscopy.
• European Crohn's and Colitis Organisation (ECCO) and ESGAR guidance on diagnostic imaging and endoscopy in inflammatory bowel disease.
• Indian Society of Gastroenterology consensus statements on the differentiation of intestinal tuberculosis from Crohn's disease.
• Digital Personal Data Protection Act, 2023 (Government of India).