In lap band surgery ,there is an inflatable silicone device placed around the top part of the stomach. It is done to treat obesity, intended to slow consumption of food and thus reduce the amount of food consumed.

Adjustable gastric band surgery is an example of bariatric surgery. It is usually done by bariatric surgeons on patients who have disorders which can be treated with weight loss. For example :

1. sleep apnea
2. diabetes
3. osteoarthritis
4. GERD
5. hypertension (high blood pressure) 
6. metabolic syndrome

The placement of band creates a smaller stomach pouch. This decreases the amount of food that can be taken at one time, thus giving the sense of satiety to be met with the release of peptide YY (PYY). It does not decrease gastric emptying time. The sustained weight loss can be achieved by choosing healthy food options, limiting food intake and volume, reducing appetite, and progress of food from the top portion of the stomach to the lower portion digestion.

The band creates a small pouch at the top of the stomach. This pouch holds approximately ½ cup of food, whereas the typical stomach holds about 6 cups of food.

Lap band surgery is done in people who have:
1. Body Mass Index above 40, or those who are 100 pounds (7 stone/45 kilograms) or more over their estimated ideal weight
2. Age between 18 and 55 years
3. Failure of medically supervised dietary therapy (for about 6 months)
4. History of obesity (up to 5 years)

Gastric banding is usually not recommended for people with any of the following:
1.If the surgery or treatment represents an unreasonable risk to the patient
2.Untreated endocrine diseases such as hypothyroidism
3.Inflammatory diseases of the gastrointestinal tract such as ulcers, esophagitis or Crohn’s disease.
4.Severe cardiopulmonary diseases or other conditions which may make them poor surgical candidates in general.
5.An allergic reaction to materials contained in the band or who have exhibited a pain intolerance to implanted devices
6.Dependency on alcohol or drugs
7.People with severe learning or cognitive disabilities or emotionally unstable people

Benefits of gastric banding :
1. Lower mortality rate: only 1 in 1000 versus 1 in 250 for Roux-en-Y gastric bypass surgery[citation needed]
2. No cutting or stapling of the stomach
3. Short hospital stay
4. Quick recovery
5. Adjustable without additional surgery
6. No malabsorption issues (because no intestines are bypassed)
7. Fewer life-threatening complications (see complications table for details)

Potential complications
1. Regurgitation of non-acidic swallowed food from the upper pouch, commonly known as Productive Burping(PBing)
2. Productive Burping is not to be considered normal. The patient should consider eating less, eating more slowly and chewing food more thoroughly. Occasionally, the narrow passage into the larger, lower part of the stomach might also become blocked by a large portion of unsuitable food.

Other complications include:
1. Ulceration
2. Gastritis (irritated stomach tissue)
3. Erosion – The band may slowly migrate through the stomach wall. This will result in the band moving from the outside of the stomach to the inside. This may occur silently but can cause severe problems. Urgent treatment may be required if there is any internal leak of gastric contents or bleeding.
4. Slippage – An unusual occurrence in which the lower part of the stomach may prolapse through the band causing an enlarged upper pouch. In severe instances this can cause an obstruction and require an urgent operation to fix.

The patient may be prescribed a liquid-only diet, followed by mushy foods and then solids. This is prescribed for a varied length of time and each surgeon and manufacturer varies. Some may find that before their first fill, they are still able to eat fairly large portions. This is not surprising since before the fill there is little or no restriction in the band.

Unlike more open forms of weight loss surgery that includes Roux-en-Y gastric bypass surgery (RNY), Biliopancreatic diversion (BPD) and Duodenal Switch (DS), the surgery of gastric banding doesn't require cutting or removing of any digestive parts. It is removable, requiring only a laparoscopic procedure to remove the band, after which the stomach usually returns to its normal pre-banded size so it is not unusual for a person to gain weight after having a band removed. However, it is not entirely reversible as adhesions and tissue scarring are inevitable.

Author's Bio: 

know more about lap band surgery and the doctor to consult for the same on the below links :

https://www.logintohealth.com/procedure/mmr/lap-band-surgery
https://www.logintohealth.com/appointment/bariatric-surgeon-and-obesity-...