Weight Loss Surgery

Gastric Bypass

Le mini BypassThe bypass consists in reducing the volume of the stomach and modifying the food circuit.


The food does not pass any more by the stomach and the higher part of the digestive tract, it goes directly in the average part of the small intestine.


The bypass acts by 4 mechanisms which join :

  • A restriction (like gastroplasty).
  • A malabsorption (the food is less digested).
  • A dumping syndrom (the sweetened food ingestion in large quantity gives a feeling of general faintness and an acceleration of the pulse, this food must thus be taken in small quantity).
  • A reduction in the rate of ghrelin, the hormone of hunger, which involves a disinterest for food (be careful : this mechanism is not effective on the possible compulsions).


  • The bypass is a complex procedure, with an avearge 6 days hospitalization.
  • The bypass leads to a very important loss of weight.
    About 5 kgs per month, during the first 6 months, then weight loss from 2 to 4 kgs per month. It is rather indicated for BMI higher than 45. According to the scientific data, the bypass makes lose - on average - 70% of weight excess after 1 year.
  • Denutrition and vitamin deficiencies are possible.
    An oral supplementation in vitamins and oligo elements is necessary.
  • The bypass is not an easily reversible procedure.
    The re-establishment of the digestive tract is a very complex procedure.
  • Food comfort is better than with gastroplasty.
    Vomiting is rare.
  • Food practices must be modified:
    3 meals and possibly 2 collations.
  • Sweetened nibbling is rather badly supported.
    Because of the '' dumping syndrom '', which is regarded as a benefit by the operated patients.
  • A regular follow-up by a multi disciplinary team is important.
    4 Blood tests are necessary the first year, then 2 blood tests per year, to seek a vitamin deficit.

The day before the procedure

  • Hospitalisation at 5 PM.
  • You can eat normally.

D day

  • No food, no drink since midnight.
  • The procedure lasts approximately 3 hours, it requires a general anesthesia and is achieved by coelioscopy.
  • After the procedure, you will spend a few hours in recovery room, before you return in your room.
  • Drugs against pain will be managed to you by venous way.
  • The evening : emply stomach.


  • No food, no drink, you must stay in bed.
  • Drugs against pain will be managed to you by venous way.
  • A kinesitherapist will come to mobilize you in your bed.


  • A kinesitherapist will help you to raise you and will make you walk.
  • A X ray of your new digestive circuit will be done.
  • After midday and the evening, you will be able to drink water.


  • A kinesitherapist will help you to raise and will make you walk.
  • The morning, you will be able to drink a tea, at midday and the evening, a soup.


  • You will be able to leave the establishment at 11 am.
  • A presciption will be given to you for vitamins and scar cares, and a seak leave from one to three weeks, according to your job painfulness.


You have usually 4 or 5 small scars on the abdomen, which are closed by fasten, of wire (which it is necessary to make withdraw) or of resorbable wire (which only leave all).


The bandages can be changed one day out of 2.
I advise you to use tight bandages, you will be able to take showers easyly.


You can make withdraw wire or fasten between D12 and D15.
It is not necessary to put bandages.
You can take showers, clean the scars with household soap, without rubbing.
Still await ten day before taking baths.


The intervention is still very close, the small stomach of the bypass is not well healed.


It is essential not "to force" the system, which could compromise its effectiveness in the following months.


I propose the following procedure : the 5 days rule.
Your hospitalization lasted 5 days.
At your exit, you must eat liquid for 5 days (water, tea, soup...)
Then you must eat crushed food for 5 days.
Then you can eat everything, while chewing food well. I advise you to crush meat for one month.


No stress, there is no reason food does not pass.

The first month

The first month enables you to be accustomed to your new digestive tract.


Eat very slowly, because you should not fill the small gastric pouch, which is healing.


After the first month

Eat in calm at regular hours.

  • Split your food catches in three meals (and, possibly, one or two collations).
  • Vary your food.
  • Eat only small pieces.
  • You must chew lengthily, and swallow several times.
  • Take time to appreciate your meal. Do not forget that digestion starts in your mouth.
  • Drink the least possible during your meals..
  • With the appearance of a feeling of satiety, imperatively cease eating.
  • Supervise your teeth

One coffee spoon moreover could make you vomit. You have only a mini gastric pouch, do not forget it.

If you vomit, Try to understand why :

  • You eat too much.
  • You eat too quickly.
  • You eat too large pieces.
  • You do not chew enough.
  • You swallow too quickly.

Beetween meals

Avoid sweetened drinks and, in theory, aerated beverages.
Often Drink apart from the meals, by small quantity, even without thirst.


Take again a regular physical activity, leisures and endurance. The simplest regular physical activity is walking : walk of a good step but at your own rythm, the ideal being 3 times 30 to 40 minutes per week.
A kinesitherapist may help you. After the first month, you can practise any sport activity.


Respect sufficient hours of sleep.
Possibly make you accompany on the level '' management of stress ''.

A regular follow up by your general practitionar is important.

In addition to your daily contribution in vitamins and trace elements, your doctor will incite you to optimize your food in the direction of a better contribution out of Iron, Calcium,(possibly after a biology of these elements).


You must be also careful with a possible proteinic denutrition. If you do not eat sufficient proteins, you will lose on your muscular masses, whereas it would be preferable to lose on your fat or water of your body. In worst case, you can undergo a protéin denutrition, with fall of immunizing defenses and a tiredness, an anaemia, a increased sensitivity to infections.


Eat well and enjoy your life !

Complications of gastric bypass are fortunately rare, but are important to know.


It is essential to evaluate the operational risk compared to the anticipated profits of gastroplasty,
before taking the decision to have an operation.


This risk is related to your medical history (cardiac, pulmonary…) and with the procedure (surgery and anaesthesia).


First week

Operational complications are possible, they can bring to stop the procedure : perforation, haemorrhage, joinings between the intestinal handles making impossible the rise of a handle to the stomach, impossibility of intubation of the trachea.


Two anastomoses are carried out, with the risk of fistulisation, requiring a new intervention, and of haemorrhage.
They are serious complications, with a vital pronostic.


The phlebitis and pulmonary embolisms are prevented by the use of anticoagulant drugs with low dose and the port of special socks.

First month

An infection on the level of a small scar is possible.

After the first month

Nutritional deficiencies are possible :

Particularly Calcium, iron, folates and B12 vitamin.
They can be responsible for an anaemia.
They are avoided by an additional contribution by oral way and regular blood analysis.


Gastric ulcer :

It is avoided by specific drugs.


Anastomosis stenosis :

It is revealed by brutal vomiting.
It requires radiographies and a scanner to make the diagnosis.


Bowel obstruction :

It is revealed by brutal vomiting.
It requires radiographies and a scanner to make the diagnosis.

Failure of bypass

Seldom the failure is complete : minim weight loss, ingestion in large quantity of liquid foods (soups) or compulsive nibbling all the day.
These food behavioral problems are often - but not always - detectable during the assessment before the intervention.
These people should not have been operated, or should have profited from a food rehabilitation during several months before the surgical procedure.

In other case, one speaks about failure when :

  • The weight loss is lower than 50% of the weight excess.
  • The patient is unhappy with his bypass : decreased food comfort, too rigorous dietetic rules, too demanding follow-up.


These failures stress the importance of the assessment before the intervention, the good knowledge of the food constraints and the anticipated results of gastroplasty.

Last update 19 August 2015