What are the long term side effects of stomach reduction?

As mentioned after the individual methods, you need food supplements for the rest of your life. Vitamin B12, for example, is absorbed in the last part of the small intestine by means of the so-called intrinsic factor, which is formed in the lower part of the stomach. Since this part of the stomach is usually “switched off” during a stomach reduction, not enough intrinsic factor is produced to absorb enough vitamin B12.
In addition, certain vitamins (especially fat-soluble vitamins A, D, E and K) and minerals can no longer be absorbed through the intestines and must therefore be administered by injection for life.
In a stomach reduction, most of the stomach is removed and the remaining stump is connected to the adjacent small intestine. As a result, the stomach is very small after the operation and patients cannot take in much food, which quickly leads to weight loss.Since the small stomach can no longer hold much volume, eating too fast or too large portions can often lead to nausea and vomiting. For this reason, affected persons must follow a strict dietary plan.
Many patients report nausea directly after eating, because their esophagus has to “fight” to transport the food into the stomach. Heartburn is also more frequent, as is the return of stomach acid (reflux) into the esophagus.
In a gastric bypass, the upper part of the small intestine is removed in addition to most of the stomach. In this part of the intestine, food components such as protein, sugar and fat are normally broken down and reabsorbed into the body.
After the operation, fewer food components are absorbed from the intestine and the incompletely digested food is transported further towards the large intestine. Doctors call this malabsorption (“poor” absorption of food components). In addition to weight reduction, this results in long-term side effects: incomplete digestion leads to malodorous flatulence, diarrhoea and fatty stools.
Due to malnutrition, many people feel weak and weakened after the operation.
Some report bad teeth due to vitamin deficiency or bad skin. The rapid weight loss often results in skin flaps. These usually have to be removed in a further operation.
The so-called “dumping syndrome” (see below), which leads to circulation problems, can also occur.
Approximately 1-2 years after the operation, weight gain of about 5-10% of the previously lost weight is often restored.
This is because the body gets used to the lower energy intake. In case of a gastric band, this can be corrected by readjusting the band, i.e. the band is tightened.
Despite all the negative consequences, for many people the positive aspects outweigh the negative. For example, blood pressure is usually lowered by weight loss.
Many people affected by diabetes mellitus type 2 have almost normal or normal blood sugar levels again after weight loss. Often knee and foot problems improve or even disappear.

The dumping syndrome is one of the side effects that can occur after stomach reduction surgery. About 70 to 75% of all patients who undergo stomach surgery suffer from dumping syndrome later.

The reduction in the size of the stomach results in accelerated gastric emptying into the subsequent small intestine, which is called dumping. A distinction is made between early and late dumping syndrome, depending on how quickly the symptoms occur after a meal. Foods that contain a lot of sugar or milk are particularly likely to cause a fall-down syndrome.

The symptoms can be alleviated by changing eating habits. In severe cases, medication can also be used for therapy.

Early dumping causes nausea, vomiting, abdominal pain, flatulence and diarrhoea within the first half hour after eating.
Late dumping is less frequent and is characterized by circulation problems, sweating, trembling and ravenous appetite.