Physiological Implications of Bariatric Surgery

One should imagine how a dose of food passes through the entire system. Any bolus starts its journey from the mouth where the jaw breaks down the food into pieces. Next shredded food goes through a windpipe, the so-called esophagus, to the stomach. The stomach works like a container that stores food while it is breaking down into nutrients. After sufficient processing, the stomach release contents into the small bowel.

According to Rehfeld, Nylander, and Karnov (2017), digestion continues in the small intestine due to the injection of bile from the liver and enzymes from the pancreas. Then a large intestine performs the transformation of digestive process waste into a water-free solid form and delivers it to the rectum for elimination. The last two parts of the alimentary canal are the rectum and anus, which are designed for controlled evacuation of stool from the system. Besides, the system includes the pancreas, liver, and gallbladder, which release secretions helpful for breaking down carbohydrates, fats, and proteins.

The most popular sorts of bariatric surgery are gastric bypass, sleeve, and band. The RYG Bypass is a procedure when a surgeon isolates a top of the stomach from the entire organ and connects it to the small intestine. As a result, the newly created tiny “pouch” needs less food to make the patient feel full, and because of the small intestine, there is less consumption of calories. Moreover, such rerouting of the digestive system is believed to increase the secretion of belly hormones that suppress hunger (Inge et al., 2016, p. 117).

The gastric band surgery is done by placing an adjustable device around the stomach to create the same small pouch. After the operation doctor can tighten the band through a port left under the skin with the help of injections of sterile saline. It works similarly to the RYGB as the band decreases the amount of food consumed and reduces hunger. However, some studies report that the transfer of food through the band is rather quick, and there is a normal level of absorption.

The sleeve gastrectomy is a technique when the surgeon creates a “sleeve” from the stomach by removing the majority of it. According to Maciejewski (2016), sleeve effectiveness seems to be almost equal to the bypass, so it helps people with obesity to lose weight, decrease hunger, and even improve diabetes. Nevertheless, there are some possible repercussions of these interventions, such as wound complication, reoperation, fracture and suicide risk, addiction transfer, etc.

Breathing starts with such external organs as the nose and mouth. Then the air passes through the pharynx and reaches the trachea, which is a windpipe situated in the chest between the lungs. From the trachea, the air reaches the bronchi and then bronchioles what are the last conductors. Air ends its journey in the tiny pouches called alveoli, which are surrounded by capillaries. Here oxygen penetrates the blood vessels through the thin walls of the alveoli by diffusion.

Next comes the second stage of the breathing process when blood carries oxygen throughout the body and delivers it to tissues. Finally, the third stage – the cells absorb the oxygen brought to them by their surface and use it for slow-burning, or oxidation. Blood captures carbon dioxide generated during that process and carries it to the lungs, where it is released when exhaled. Extra weight also influences the performance of the respiratory system. People with obesity are spotted to have a weaker heart, which leads to a decrease in the effectiveness of breathing. Moreover, obesity leads to the mechanical pressure of the lungs and diaphragm. Such pressure can cause pulmonary damage and reduce the strength of muscles needed for breathing.

To conclude, all bariatric surgery types predominantly deal with the stomach as the most important organ in the digestive system. Doctors create a small sack from the entire stomach what leads to less food consumption by the patient, and he/she has a lower hunger. The respiratory system also suffers from the extra weight so that bariatric surgery might be a solution to this problem as well.


Inge, T. H., Courcoulas, A. P., Jenkins, T. M., Michalsky, M. P., Helmrath, M. A., Brandt, M. L.,…&Horlick, M. (2016). Weight loss and health status 3 years after bariatric surgery in adolescents. New England Journal of Medicine, 374(2), 113-123.

Maciejewski, M. L., Arterburn, D. E., Van Scoyoc, L., Smith, V. A., Yancy, W. S., Weidenbacher, H. J.(2016). Bariatric surgery and long-term durability of weight loss. JAMA Surgery, 151(11), 1046-1055.

Rehfeld, A., Nylander, M., &Karnov, K. (2017). The Digestive System I: The Alimentary Canal. In Compendium of Histology (pp. 433-473).Springer, Cham.