Dumping syndrome

Dumping syndrome, or rapid gastric emptying, occurs when food moves too quickly from the stomach to the bowel. Whilst it is very rare in those born with short-gap OA, it occurs relatively frequently in long-gap OA. There is good research on the condition in those with long-gap OA repaired by gastric pull-up. Hannon et al. (2020) (31) found 12% of their cohort were formally diagnosed with the condition, whilst 25% were symptomatic but had yet to be formally diagnosed. The research is scanty in those with jejunal or colonic interpositions, but there are a number of adults with these oesophageal replacements who have this diagnosis. However, even some with short-gap OA have dumping syndrome, secondary to anti-reflux surgery, and in fact anti-reflux surgery is the main cause of the condition in childhood. It has also been found in short-gap OA in the absence of anti-reflux surgery, and this is thought to be due to vagal nerve damage during repair triggering abnormal gastric emptying, alongside the congenital neuromuscular anomalies in oesophageal and gastric emptying. (59)

Symptoms

Early dumping systemic symptoms

Within the first hour after the meal, due to rapid transit of nutrients to the small intestine:

• Desire to lie down
• Palpitations
• Fatigue
• Faintness
• Syncope (sudden loss of consciousness)
• Diaphoresis (sudden onset of sweating)
• Headache
• Flushing

Early dumping gastrointestinal symptoms

Within the first hour after the meal:

• Epigastric fullness
• Diarrhoea
• Nausea
• Abdominal cramps
• Borborygmi (loud bowel noises)

Late dumping symptoms

Occurs one to three hours post meals:

• Perspiration
• Shakiness
• Difficulty concentrating
• Decreased consciousness
• Hunger

Weight loss and lower body mass index (BMI)

There is good research to show that many patients lose weight post anti-reflux surgery or oesophageal surgery in adulthood, due to the symptoms of dumping syndrome and avoiding eating or modifying the diet to avoid symptoms. (60)

Investigations

Whilst there are a number of investigations that can be used to aid in diagnosis, a symptom-based questionnaire can also be used whilst waiting for these to be done. All of the investigations below necessitate referral to secondary care:

1. Oral glucose tolerance test is the gold standard for diagnosis.
2. Hydrogen breath test post ingestion of glucose.
3. Gastric emptying study – can be done to determine likely neuromuscular causes but not diagnostic for dumping syndrome.
4. Barium swallow and gastroscopy can help assess the anatomy but don’t help in diagnosis. (60)

Treatment

• Dietary modification is first line of treatment, and dietitian referral. The recommended changes include daily nutritional intake being divided into six small meals. For most with dumping syndrome, fluid intake with meals is restricted, but this isn’t possible in OA/TOF. Rapidly absorbable carbohydrates, eg sugary foods such as sweets, sugary breakfast cereals, honey, syrups and sugary drinks, should be avoided. Nutrient-rich supplement drinks (milkshake/juice style) commonly advised by healthcare professionals may make symptoms worse due to their high sugar content. Eat more complex carbohydrates like whole grains, pasta, potato, rice, wholemeal breads and unsweetened cereal.

Include a protein source at each meal, eg eggs, meat, poultry, fish, milk, yogurt, cheese, pulses and nuts. Foods high in soluble fibre slow gastric emptying and prevent sugars from being absorbed too rapidly. Foods high in soluble fibre include: broccoli, Brussels sprouts, carrots, nuts, oats, okra, peas, pears, prunes, pulses and soya beans.

Eat slowly and chew food thoroughly. Avoid alcohol. (59)

• Acarbose can slow carbohydrate absorption and in turn hypoglycaemia in late dumping, but are less useful in early dumping, which represents most patients with OA/TOF.
• Somatostatin analogues, such as octreotide, are able to slow the rate of gastric emptying, slow small bowel transit, inhibit the release of gastrointestinal hormones, inhibit insulin secretion and inhibit postprandial vasodilation (60)

Recommendations

A multinational Delphi consensus process produced the following recommendations for diagnosis and management of dumping syndrome. (61)

The presence of symptoms suggestive of early or late dumping syndrome in a patient who has undergone oesophageal or gastric surgery should raise clinical suspicion. Patients often mention the need to lie down after meals due to profound weakness.

The modified oral glucose tolerance test is the preferred diagnostic method to confirm the diagnosis of dumping syndrome.

Dietary measures, focusing on low-volume meals with elimination of rapidly absorbable carbohydrates and delay of fluid intake, are the preferred initial approach.

In patients who do not respond to diet modification, the use of acarbose is recommended, especially for late dumping syndrome, but with an unclear effect on early dumping syndrome.

In patients who do not respond to diet and/or acarbose, somatostatin analogues can control symptoms of both early and late dumping syndrome. It is unclear whether short-acting analogues are superior to long-acting formulations.