Managing possible side effects

It is normal to have some difficulties with eating and drinking after weight loss surgery. These problems usually happen during the early stages after surgery because you are healing and adapting to a new way of eating, which can take time.

Pain or discomfort

Eating or drinking too fast or too much at one time can cause pain or discomfort. 

Try taking smaller mouthfuls (size of a 20p coin) and chew food to a paste before swallowing. Avoid gulping. Wait for each mouthful to go down before taking the next. Stop eating as soon as you feel full and before you become uncomfortable.

Being sick or regurgitation

Vomiting (being sick) and bringing food or fluid back up (regurgitation) can happen when you:

• eat or drink too fast
• eat or drink too much at one time
• do not chew food to a paste before swallowing
• eat or drink beyond the point of fullness
• eating and drinking too close together

Try to avoid drinking 30 minutes before and after eating.

You might be sick or regurgitate food if you move to the next stage too soon.

Finding it hard to poo (constipation)

Not having enough fluids and becoming dehydrated can cause constipation.

Try to have 2 litres of fluid each day.

You might also have constipation if you are eating less than your body is used to (this is unavoidable), or eating less fibre than usual.

Speak to your dietitian or healthcare professional if you want information on how to have more fibre.

You might need to have medicines for constipation (such as a stool softener or laxatives). 

Runny poo (diarrhoea)

Eating or drinking foods that are too high in sugar or fat can cause diarrhoea. 

Dumping syndrome

Around 3 in 4 people (75%) who have had gastric bypass surgery have dumping syndrome. This is a condition which happens if you eat or drink too much sugar, have large amounts of food, or eat and drink at the same time.

The symptoms can be very unpleasant, and can include:

• feeling sick or being sick
• diarrhoea
• sweating
• feeling faint or weak
• increased heart rate

Dumping syndrome can happen shortly after eating (10 to 30 minutes) or later after eating (1 to 3 hours). The symptoms usually pass after 2 to 3 hours.

To avoid these symptoms, do not have sugary foods and drinks (including fruit juice). Eat smaller portions and avoid drinking with meals. Some people have similar symptoms to dumping syndrome if they have too much alcohol or fat.

Try keeping a food and symptom diary to find triggers for these symptoms. Contact your dietitian if the problem continues.

When to get help