Pre-op gastric bypass FAQs

If you are unsure about anything relating to your procedure call us. Our team is here to help. Some common questions are shown below.

What symptoms are common after surgery?

  • Fatigue: For the first two weeks after your operation you are likely to feel tired and although we would encourage you to walk daily, don’t overdo things. Even when your wounds look healed on the outside, they are still healing inside
  • Diarrhoea: Some people develop quite severe diarrhoea in the first few weeks after surgery. This can be due to changes in your medications, the change to a liquid diet or an increase in your milk consumption. Make sure that you drink even more fluid to replace what you are losing. If the diarrhoea is particularly troublesome get your GP to check that you do not have ‘overflow diarrhoea’ or an infection. The bypass is unlikely to be the direct cause
  • Constipation: More commonly, your bowel frequency will be much less than before surgery because you are now taking much smaller quantities and there is very little fibre in your liquid diet. If you suspect that you are constipated, follow this advice:
    • Make sure you are drinking at least 1.5 litres of fluid per day
    • Include 1-2 cups of diluted fruit / vegetable juice per day or try syrup of figs or prune juice as a gentle bowel stimulant
    • Make sure that you are active and not sitting or lying around too much
    • If it is still a problem, take a non-bulk forming laxative such as lactulose (Duphulac), or Senokot Syrup. You should avoid taking bulking agents such as Fybogel which could cause a blockage in the smaller stomach.

What should I do if I am regurgitating food / vomiting?

Occasional vomiting after gastric bypass surgery is not uncommon but you should check the following:


Will I only be able to eat tiny amounts for the rest of my life? Will I be able to eat regular food?  
At the beginning you will likely only eat approximately two to four tablespoons of food. You will gradually advance your diet and by around eight weeks you should be eating “regular” food. Your capacity will increase over the first six to nine months of surgery. The stomach and small intestine learn how to work together over a period of months. Many patients notice a dramatic increase in the amount of food they can handle comfortably. This is normal in most cases. This is the time when the good habits developed in the first few months will support further weight loss.  

How do I get my protein in when I can eat such little amounts?  
Following your surgery, it is important for healing, as well as to aid weight loss that you consume an adequate amount of protein. Since you are limited in your food intake, it is recommended that you follow a diet which is low in fat and sugar, and high in protein.  The foods outlined in the nutrition section above are an excellent guide and you can supplement your protein intake if you wish, by using  Weight to Go high protein shakes and porridge. Maintaining a high protein intake not only increases the sense of satiety (fullness) but also helps to preserve lean (muscle) mass.   

Do I have to take vitamin and mineral supplements for the rest of my life?  
Yes.  Because gastric bypass limits absorption of calories, it can also limit the absorption of essential vitamins and minerals. This is why daily vitamin and mineral supplementation is essential to your long-term health following gastric bypass. If you are unsure about what is required refer to your surgery pack or feel free to call our team. 

What about blood tests?  
To ensure that you are maintaining the necessary levels of essential vitamins and minerals, you will need to have regular blood tests for the rest of your life. In the Healthier Weight package, your first blood checks will be carried out at 6 and 18 months, then followed up by GP annually.  Depending on the results, the doctor will then be able to advise you on future testing frequency.   

What is “dumping syndrome”?  
Dumping syndrome is a group of signs and symptoms that develops most often in people who have had surgery to remove all or part of their stomach, or in whom much of their stomach has been surgically bypassed to help lose weight. It may occur early or late. Dumping tends to decrease over several months as the pouch and small intestine learn to work better together. Although dumping is uncomfortable, it is not dangerous.

Early dumping – (rapid gastric emptying) typically starts during a meal or within 15-30 minutes following a meal.  It is caused by foods which are high in sugar passing too quickly from the stomach into the small intestine.  Because the food is very concentrated (dense) it attracts a correspondingly large amount of fluid into the gut causing it to become stretched and painful.  Symptoms include 

  • Nausea
  • Vomiting
  • Abdominal pain, cramps
  • Diarrhea
  • Dizziness, lightheadedness
  • Bloating, belching
  • Fatigue
  • Heart palpitations, rapid heart rate


Late dumping (rapid gastric emptying) typically occurs 1-3 hours after eating. Late dumping is caused by marked fluctuations in blood glucose levels among patients whose digestive anatomy has been altered by surgery, like gastric bypass. When sugar is eaten it is quickly absorbed into the bloodstream triggering a rapid rise in blood sugar levels. The pancreas responds by secreting an equally large amount of hormones to deal with the excess blood sugar.  However, sometimes the pancreas produces too much of these hormones, resulting in a low blood sugar level (hypoglycaemia). Symptoms include:  

  • Sweating
  • Weakness, fatigue
  • Dizziness, light-headedness
  • Shakiness
  • Feelings of anxiety, nervousness
  • Heart palpitations, rapid heart rate
  • Fainting
  • Mental confusion


If you experience late dumping you need to eat a glucose sweet (anything sweet will do) immediately.  Then eat something which is lower in sugar – eg. crackers, wholemeal biscuits, yoghurt etc.   

Tips to avoid both early and late dumping

  • Avoid problem foods. Everyone tolerates food differently so avoid foods that you know cause you problems
  • Eat smaller meals. Try taking 5 or 6 small meals a day rather than two or three larger ones
  • Avoid drinking liquids with your meal. Drink up to 15 minutes before and wait for 1 hour after your meal
  • Eat fewer foods containing sugar and simple carbohydrates such as sweets, chocolate, ice-cream, cakes, biscuits etc. Read labels on packaged food and try to avoid foods containing sugar or sugar alternatives such as glucose, sucrose, fructose, dextrose, honey and corn syrup. Artificial sweeteners are acceptable 
  • Consume more protein in your diet, and adopt a high fibre diet with more fruit and vegetables
  • Increase your pectin intake, found in fruits such as peaches, apples and plums as it can delay the absorption of carbohydrates in the small intestine. It can also be found in some fibre supplements 
  • Avoid acidic foods such as tomatoes and citrus fruits as these are harder for some people to digest
  • Use low-fat cooking methods, prepare your meat and other foods by baking or grilling
  • Make sure you are taking your vitamin and mineral supplements as prescribed
  • Lie down after eating as this may slow down the movement of food into your intestines
  • If you suffer with hypoglycemia (low blood sugar), avoid sugar and sweets that can cause ‘late dumping’
  • Avoid foods that are very hot or very cold as they can trigger these symptoms  

Will I lose all my hair? How do I keep it from falling out?  
While not all patients lose some hair after the bypass, many do. The reason has to do with weight loss and not surgery. Anyone who experiences a rapid, sustained weight loss may experience some temporary hair loss as well. This usually occurs between the fourth and the eighth month after surgery. You can help by maintaining a high protein diet, keeping well hydrated and taking your daily vitamin and mineral prescription (especially zinc). You may also find kelp (a seaweed extract available from health food shops) helpful. Almost all patients will experience natural hair re-growth after the initial period of loss. 

Can I get pregnant after weight loss surgery?  
When a woman of child-bearing age undergoes gastric bypass surgery, one of the first things she will hear from the nay-sayers is that after surgery she cannot have a healthy pregnancy because of presumed nutritional deficiencies. The contrary is true. Morbid obesity results in a high rate of complicated pregnancies and a high rate of miscarriage. Women who become pregnant after achieving weight loss with gastric bypass generally have lower risk pregnancies than morbidly obese women.

So if you are a woman of child-bearing age and in otherwise good health, you should be able to have a baby after this surgery. It is strongly recommended that women wait at least one year after the surgery before a pregnancy. Approximately one year post-operatively, your body will be fairly stable (from a weight and nutrition standpoint) and you should be able to carry a normally nourished foetus. You should consult your weight-loss specialist as you plan for pregnancy. 

Can I still take all my medications after the bypass?  
Food passing out of your new stomach pouch must squeeze through a new small opening before it gets into the normal digestive tract. This hole, or stoma, will dictate what size medications can pass through to your digestive system. Pills or capsules that are small enough will pass through the stoma without a problem.  But to be safe, you may want to crush all your medications or find liquid substitutes for them.  Not all pills can be crushed (e.g. slow-release) and some are unpalatable in a crushed form.  Speak to your doctor about which of your medications can be taken in liquid form and which can be crushed.

Are there any medications that I must avoid altogether?   
Some medications are not to be used because they may cause ulcers or inflammation in your stomach pouch.  You should permanently avoid using any type of non-steroidal anti-inflammatory drugs also known as “NSAIDs”, which include pain relievers such as aspirin, Ibuprofen, Diclofenac, Sulindac, Celecoxib, Diflunisal,  Naproxen, Piroxicam etc.  If you are unsure, ask the Healthier Weight Centre for advice. 

Wound FAQs 

When can I shower or bathe?  
We advise that you keep the wounds as dry as possible and avoid showering for 10-days, please also be careful when bathing. This is because if the wounds get wet, there is a significantly increased risk of developing a wound infection. When you start to shower or bathe, gently pat the wounds dry with a clean towel and avoid rubbing. However, if you have had glue applied to your wounds it is quite safe to shower immediately after your surgery.  

How long will it take for the wounds to heal?  
Usually your wounds will be healed in about two weeks following the procedure. However, some heal faster than others so please don’t be alarmed if yours take a few days longer.    

Is it normal for the wound to itch?  
Yes. This is a normal accompaniment to wound healing and is probably due to new skin and nerve endings growing into the area.  However, it may also be due to a skin reaction to the dressings used to cover the wounds. If it becomes a problem, please contact your Bariatric Nurse for advice.  

How do I know if the wound is infected?  
If a wound becomes tender, looks inflamed, red or swollen, or if it weeps offensive smelling liquid, pus or blood, you should speak to your Bariatric Nurse. However, redness on its own is not necessarily a sign of infection.  

What about antibiotics?  
If your wound does become infected, it will be necessary for you to take a course of antibiotics. We recommend Augmentin for which you will need a prescription from your GP. Healthier Weight do not have the facility to issue prescriptions. 

Call our specialist team today on
0800 313 4618 
Get a quote 
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