Gastric Bypass Side Effects

Gastric Bypass Side Effects

Everything you need to know about gastric bypass side effects

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Gastric Bypass side effects, can occur when the team does not have the appropriate experience and technical means to perform these interventions and in these patients so special.

Bariatric and metabolic surgery is a complex specialization, which requires not only many hours of dedication and a well-graded and tutored learning, but also, the surgeon must finally be able to carry out these operations with dexterity, safety and minimal adverse effects. Due to the complexity of these techniques and patients, surgeons are not always successful despite many dedicated hours. In that case, we usually meet with surgeons who have more complications than are statistically admissible.

The most frequent severe Gastric Bypass Side Effects are:

Let’s go commenting each one of them.

5 Gastric Bypass Side Effects

The following are the most common gastric bypass side effects, although, they occur in a very small percentage of cases.

Leak or fístula

Fistula - Gastric Bypass Side EffectsIt is a failure in any of the areas where the intestine is opened or sectioned, with the intention of changing its morphology or joining it to another intestine (anastomosis). These occur, it always happens in the first postoperative days (1 to 5 days), although sometimes they appear later (that is to say they existed from before, but so small that they were not manifested. The most common is that they are diagnosed in the first 48 to 72 hours, although “you have to think about them” to be able to diagnose them as soon as possible. It is considered the most severe of all gastric bypass side effects, and in the hands of highly experienced surgeons and equipment, its incidence should be less than 0.5-1%. We are convinced that thorough tissue management and good surgical technique with sufficient safety measures (not all Gastric Bypass operations are performed at the same safety levels) should have a complication rate below 1% . The management of this complication is very complex. The experience of the surgical team is fundamental, and support by radiology and interventional endoscopy is often necessary. Therefore a good team of bariatric and metabolic surgery must have these specialists, and with adequate advanced training. The possible solutions, almost always go through a re-intervention, associated with cleaning the abdomen, antibiotics and special nutrition for days or weeks. If diagnosed and treated correctly, the possible mortality from this complication should be exceptional.

Peritoneal or intraluminal hemorrhage

Peritoneal hemorraghe - Gastric Bypass Side EffectsIt involves a patient bleeding into the tissues that have been handled during the operation, either into the cavity of the abdomen, or into the lumen of the intestine. Of course, at the end of a gastric bypass procedure, hemostasis is thoroughly checked, and the operation is never completed until everything is perfectly bleeding (no bleeding) and completely overhauled. However, in very few cases (less than 1% when tissues are handled correctly and with advanced hemostasis systems -ultracision, ligasure or similar-) the patient may bleed within 5 to 12 hours after the operation. Excess bleeding, which may be encapsulated in the liver or spleen, or other rare causes, are exceptional.) This is the second most severe side effect after a Gastric Bypass, however, its solution is simpler, if the equipment that operates the patient has an early diagnosis protocol of bleeding, and immediate action, of the same equipment that has operated. With an expert diagnosis and in time, and with a therapeutic intervention appropriate to the gravity, carried by the same team of experts as we said, it is not a cause to have mortality. Let’s say that all cases must be able to be solved, although there can always be an exception. We have had an incidence of bleeding of 1%, and no case of mortality due to this cause.

Intestinal obstruction

Intestinal Obstruction - Gastric Bypass Side EffectsIt is an obstruction of the lumen of the intestine, so that the food can no longer continue with its progression to the large intestine, and that happens as a consequence of the anatomical changes that we perform in this surgical technique. The most frequent is that the obstruction is due to a plication or bend of a handle of intestine, hands frequently to a corkscrew type twist. This complication manifests as colicky pain associated, not always, with a sensation of obstruction or intestinal stoppage. It often resolves spontaneously, although another requires a surgical revision (reoperation), which should always be approached by laparoscopy, and if possible by the team that initially operated on it. It can manifest from weeks of operation until years later. The surgical solution is usually simple and effective, and the key is the diagnosis, which can be difficult if you do not think about it. That is why we train our patients and warn them of this possibility, although so far we have not had any cases of intestinal obstruction. They can suffer about 3% of patients operated on Gastric Bypass, although in the past it happened up to 15-20%. This is a side effect after a Gastric Bypass, with a solution almost always simple, and the key is that it can be diagnosed in time, to avoid the suffering of the obstructed intestine. In fact, it could exceptionally have serious consequences.

Marginal ulcer

Marginal ulcer - Gastric Bypass Side EffectsIt is one or more small ulcers that can appear most often in the area of ​​small intestine that has been attached to the small stomach that we left in this operation. The patient perceives it with the same symptoms as a patient suffering from ulcer (stomach pain and feeling of acidity). They may bleed or perforate if the patient is not cared for and treated properly. Its incidence is low, 2-3, and is almost always related to tobacco use, and poor care after a Gastric Bypass operation (long periods of fasting, irritants, spicy, professional or personal stress …). Therefore it is important to take care of these aspects after a Gastric Bypass surgery, and they should also be taken into account before indicating this operation. In a patient who will not be able to perform minimal care, a Gastric Bypass should not be indicated, and it would be better to indicate a Gastric Tube or Vertical Gastrectomy surgery. The treatment usually suffices with, apply the mentioned care and take appropriate antacid treatment, apart from the specialized medical follow-up. It is a side effect after a Gastric Bypass, less severe, of easy solution, although occasionally there may be cases that do not improve and that could force a revision of the operation (re-operation).


Malnutrition is another of the gastric bypass side effects, exceptional, as long as the standard requirements for Gastric Bypass surgery accepted by the Scientific Societies are applied. However, this DOES happen with some frequency when they are performed malabsorptive operations, such as the MINIGASTRIC BYPASS or BYPASS OF A SINGLE ANASTOMOSIS, BYPASS BILIOPREANCREATICO, or DUODENAL CROSS. Such interventions are performed by a limited number of surgeons in Spain, Italy and Greece, and are generally practically not used in the US because of their adverse effects. Patients suffer from frequent diarrhea in relation to meals, sometimes near or immediate to food, with flatulence and unpleasant body odor, which prevents them from normal social life.

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Gastric Bypass Side Effects August 29, 2017

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We are a multidisciplinary team, focused in the treatment of patients with overweight, obesity and related diseases. Our team are highly trained and experience to help you to lose weight, in a healthy way, with minimal risk, making your surgery a pleasant experience, guarantee you excellent and long lasting results. Our goal is improve your health, transforming your life.

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Cirugia para Obesidad y Diabetes
Av. Morones Prieto Pte. 3000, Centro de Enfermedades Hepáticas, Hospital San José, Los Doctores Monterrey, NL 64710
Phone: +52 81 1365 9490