The stomach can usually hold large amounts of food before gradually releasing it into the small bowel. But, after your stomach operation this will change. 

If you have had part of your stomach removed, the remaining stomach won’t be able to hold as much food as before and you’ll need to eat smaller meals to begin with. Over several months the stomach gradually stretches so that eventually most people are able to eat as they did before the operation.

If you have had all of your stomach removed, the food that you eat will go straight from your gullet into the small bowel. Normally food is broken down and absorbed in the bowel, so this won’t affect your ability to digest food. But, the small bowel won’t be able to hold as much food at one time as your stomach could. So you will need to eat smaller portions of food and eat more often. In time your body will adjust and you will be able to eat more at a time.

After your stomach operation you will feel full quite quickly when you eat or drink. So you’ll need to eat several (about six) small meals a day, rather than a few larger meals. Some people plan this as a light breakfast, lunch and evening meal, along with a mid-morning, afternoon and evening snack. It’s also best to have drinks separately from meals (or just drink a small amount with your meals).

Eating a balanced diet will help you to gain weight, and recover more quickly. However, you may not feel much like eating for some time after the operation, so don’t be worried if it takes you a couple of months to get back to eating a balanced diet again. You may find that certain foods make you feel sick, or give you indigestion or diarrhoea. Keeping a food diary where you note down which foods you eat and any problems you have, will help you to begin to know which foods may cause you problems.

If you are losing weight you will need to increase your calorie and protein intake. A good way of doing this is by having nutritious, high-calorie drinks. There are several different types. They are available on prescription from your doctor or you can buy them at most chemists. Always carry a snack with you when you go out as this can help you to eat more. Another way of improving your appetite is to have a glass of sherry (or another type of alcoholic drink) about half an hour before a meal – but check with your doctor first as some medicines shouldn’t be mixed with alcohol.

Trying to put weight back on can be difficult. Many people struggle to keep their weight steady to begin with. Some people never regain all of the weight that they have lost. But, in time most people find that their weight becomes steady again, although they may weigh less than before.

It can be very helpful to talk to a dietitian. They can give advice and information about possible changes to your diet. Most hospitals have a dietitian available and the staff on the ward can arrange for them to visit you. Your GP may also be able to refer you to a community-based dietitian.

After your operation your body may not be able to absorb certain vitamins and minerals as well as before.

Vitamin B12 plays an important role in making healthy red blood cells. A special chemical called intrinsic factor enables us to absorb vitamin B12 from the food we eat. Intrinsic factor is only made in the stomach, so if you have all of your stomach removed you will need to have a vitamin B12 injection every few months.  If only part of your stomach is removed your doctor will do a blood test to check your levels of B12 from time to time in case you should need injections.

You may find it helpful to read our sections on diet and cancer and dietary problems after surgery.

Normally, the stomach stores food and releases it into the bowel in a controlled way. After an operation to remove part or all of your stomach this process can be affected causing symptoms that are known as dumping syndrome. There are two types: early dumping syndrome and late dumping syndrome.

Early dumping syndrome refers to symptoms that may happen within 30 minutes of eating a meal. You may feel dizzy, faint, and your heart may start to beat faster. These symptoms may last for about 10–15 minutes. Some people also have tummy cramps and diarrhoea.

The symptoms happen when food rapidly enters the bowel. This draws fluid into the bowel from the surrounding organs and tissues and causes a drop in blood pressure.

If you have symptoms of early dumping syndrome you may be able to reduce the problem by:

• eating slowly
  
• taking small, frequent, dry meals
  
• having drinks between meals, rather than at mealtimes
  
• avoiding meals that are mostly made up of foods high in added sugar, such as sugary cereals
  
• eating meals that are high in proteins such as fish, meat and eggs and starchy carbohydrates like pasta, rice, bread and potatoes
  
• resting for 15–30 minutes immediately after meals.

Many people find that early dumping syndrome gets better on its own in time. And, that symptoms get less severe and happen less often after a few months.

Late dumping syndrome usually happens a couple of hours after meals or when a meal has been missed. You may suddenly feel faint, sick and shaky. The problem is caused by low blood-sugar levels.

You can help to prevent or lessen late dumping syndrome by following the advice for reducing the symptoms of early dumping syndrome. If you feel the symptoms coming on, taking glucose tablets may help you to feel better.

If your symptoms continue or are severe your doctor may prescribe a medicine, such as octreotide or a similar drug to help. In most people the symptoms of dumping syndrome become less severe and happen less often in time, but let your doctor or dietitian know if it continues to be a problem.