Bariatric surgery includes several surgeries that the surgeon performs to reduce weight. The surgery involves alterations in the digestive system. Some procedures of bariatric surgery reduce the absorption of nutrients. Other procedures limit the amount of food intake. Therefore, the person must make permanent changes in their dietary habits to obtain maximum benefit from bariatric surgery.

1. The digestive system of the human comprises mouth, oesophagus, stomach, small intestine, large intestine, and anus. The digestion initiates in the mouth, where the food is mixed in the saliva.
2. The food then reaches the stomach, where the gastric acid and other enzymes break the food into small components for absorption. The food enters the small intestine. The pancreatic juice and bile mix for further digestion.
3. The concept behind bariatric surgery is to alter the digestive system to reduce digestion and absorption. The reduced amount of nutrients and calories results in weight reduction.

The doctor advises the patients to undergo bariatric surgery in the following cases:

1. People who cannot lose weight through one or more of the non-invasive methods.
2. Overweight or obese people who are at high risk for developing or are suffering from hypertension, cardiac disease and stroke, type 2 diabetes, sleep apnoea, and non-alcoholic steatohepatitis or non-alcoholic fatty liver disease

It is necessary to note that bariatric surgery is not for all people who are obese or overweight. The surgeon comprehensively screens the patients to determine their eligibility for bariatric surgery.

The doctor generally performs the following three types of bariatric surgery:

1. Gastric bypass Surgery:  In this surgery, the surgeon transforms the stomach into a small pouch and attaches the small intestine into the pouch. It is a common method and is usually irreversible. After this procedure, the food bypasses most of the stomach and the initial part of the small intestine.  
2. Sleeve gastrectomy: During this procedure, the surgeon eliminates most parts of the stomach to make the stomach a thin-tube like structure. Thus, the new stomach would be unable to hold much food. There is also lesser secretion of the hormone ghrelin resulting in lesser appetite. 
3. Biliopancreatic diversion with duodenal switch: This procedure is done in two steps. The first step is similar to sleeve gastrectomy. The surgeon makes the stomach into a tube-like structure. In the second step, the surgeon bypasses a significant portion of the intestine.
4. Gastric band: The surgeon, during this procedure, places a silicone band around the upper stomach to reduce its size. The surgeon also attaches this silicone band to a tube and extends it under the abdominal skin. The surgeon inflates the silicone band by injecting the saline solution into the tube.

Before the Bariatric Surgery

1. Once the surgeon advises you to undergo surgery, he will recommend a pre-anaesthesia assessment. 
2. The anaesthetist performs the assessment and may ask you about your medical history, allergies, and other underlying medical conditions. 
3. The anaesthetist may also refer you to a specialist to optimise the treatment for other medical conditions. 
4. The doctor may advise you to stop medications that increase the risk of bleeding, such as aspirin or NSAIDs, one week before the surgery. 
5. The doctor may also advise you to stop herbal supplements before surgery and recommend the bariatric-friendly diet that you need to take. 
6. Your doctor may also adjust your medications for other medical conditions, such as diabetes or cardiovascular diseases.
7. You need to stop eating or drinking at least a night before the day of surgery.
8. Your doctor may recommend you to start the routine exercise.
9. If required, your doctor may advise you to take the services of a psychological expert to reduce your surgery anxiety.
10. Your doctor may also provide you with complete details about the type of surgery, the possible outcomes, recovery, cost, and complications.
11. Ask questions you have related to the surgery. 

On the day of Bariatric Surgery

1. The hospital's administrative staff gives you the surgery's time and date. It would be best to reach the hospital at least 2 hours before the scheduled time to make yourself comfortable.
2. Wear clean and loose clothes.
3. Do not bring any valuable items to the hospital, such as jewellery or a watch. 
4. Once you reach the hospital, the staff will ask you to fill out the informed consent form and pay the fee for surgery.
5. The hospital staff will check your overall health, such as temperature, oxygen levels, blood pressure, heart rate and respiratory rate.
6. You will then be shifted to the hospital.

During the Bariatric Surgery

You may expect the following during the bariatric surgery:

1. The surgery procedure depends upon the type of surgery decided by the surgeon.
2. For laparoscopic surgery, the doctor will make multiple small holes, while in open surgery, the surgeon will make an 8 to 10-inch long single incision. 
3. The surgery is performed under general anaesthesia.
4. The staff will insert an IV line to administer drugs and fluid during the surgery.
5. The staff monitors the vitals throughout the surgery.
6. The surgeon closes the incision after the surgery with the help of sutures. The bandage is placed on the wound to cover it.

After the Bariatric Surgery

1. The staff will shift you to the recovery room. The nurse attaches various machines and monitors the vital parameters.
2. Once your condition is stabilised, you will be shifted to the general ward.
3. The doctor may prescribe antibiotics to prevent infection and analgesics to provide relief from pain.
4. The doctor may instruct you not to eat one to two days after the surgery. It will allow the tissues of the stomach and intestine to heal.  
5. You may be discharged within one to three days after the surgery, depending upon the type of surgery and your overall health.
6. The doctor will give you detailed instructions regarding diet and other activities during discharge.
7. Your doctor may recommend you on a healthy diet and incorporate exercise in your daily routine to maintain your weight.

First Follow-up Appointment

1. Your doctor will provide the date for the first follow-up visit after bariatric surgery.
2. Do not miss the follow-up visit and go to the hospital for the first and subsequent visits.
3. During the visit, the doctor may ask you about the pain and other symptoms you may be experiencing, such as nausea and vomiting.
4. The doctor may ask you to undergo imaging tests to provide a clearer view of your recovery.
5. The doctor may also discontinue some medications.

Bariatric surgery is a safe surgery with a low risk of complications during and after. However, patients should not ignore the warning signs after being discharged from the hospital. Consult your doctor in case you experience the following symptoms:

1. Chest pain
2. Abdominal Pain (that may be a sign of gallstones which can develop in case of sudden and substantial weight loss)
3. Burning sensation in the chest
4. Nausea and vomiting
5. Chills and fever
6. Swelling and pus formation at the site of the incision
7. Pain in the stomach (maybe due to stomach obstruction)

There are several effects due to delayed bariatric surgery.

1. Patients also need to undergo bariatric surgeries as a prerequisite for another surgery.
2. For instance, people requiring a kidney transplant or hip surgery are advised to undergo bariatric surgery to reduce weight. Further, it has been found that delay in bariatric surgery reduces the overall quality of life.
3. Delay in bariatric surgery may increase the severity of arthritis and joint pain. In addition, patients have reduced exercise ability and poor mobility.
4. Further, the risk of other diseases predisposed to obesity and overweight also increases, such as cardiovascular disease, dyslipidemia, and diabetes.