Why is bariatric surgery generally performed on the stomach and not the intestines?

[Bohandas]

As the thread title says, why is bariatric surgery generally performed on the stomach and not the intestines?

It always seemed to me that it would make more sense to remove part of the intestine because this would reduce the amount of fats and sugars coming into the body without necessitating any change in the patiemt's lifestyle, whereas normal bariatric surgeries strike me as merely being overly complicated dieting aids. Is there any reason for the surgery to be performed on the stomach rather than the intestines (other than perhaps a paternalizing belief that eating less should be the only way people are allowed to lose weight)?

[snowblizz]

At a guess, they go for the more easily workable organ. Putting a band around the gut is a much less intrusive then cutting out a piece of the intestines and trying to stitch it together and make sure it doesn't leak.

Also, presumably, working with intestines might not trigger the hormonal response they are after.


When I ended up in for gall surgery I asked why they had to remove the entire bladder, why not just slice it open and empty it. Apparently there are risks with leakage in that scenario. Am thinking cutting the intestine tract in 2 places means they are working with more easily damaged organs.


I''m quite sure the reason they work with the stomach is because that's what is going to do the most good with the goal in mind with the least surgical impact.

[factotum]

Well, pretty obviously something like a gastric band is something that can be fitted without actually cutting any holes in the digestive tract whatsoever, which makes it a far less intrusive operation than cutting out a chunk of intestine and sewing it back together would be--especially considering that the gut is full of nasty bacteria that you really don't want getting out into the abdomen. For the same reason, the contents of the stomach (mostly digestive acids) are less dangerous than gut bacteria.

[Fat Rooster]

It reduces nutrient uptake, but not all nutrients equally. In particular it would have almost no impact on sugar uptake, and little impact on starch. Matched with a poor diet the patient would actually be at greater risk of malnutrition, while not losing any weight. Their appetite may actually increase, causing them to gain weight. Without reducing portion size sugar peaks would be unchanged, meaning diabetes would be unmitigated.

People with damaged digestive tracts are required to be careful about their diet, and the people for whom a gastric band is appropriate are those least able to apply that care. Instead of their eating habits killing them by complications from obesity, it will kill them more directly by aggravating damage to their digestive tract, while providing no real assistance in changing those habits.

In short, on top of being directly dangerous as other have mentioned, it would be largely ineffective. Good question though.

[Eldan]

The digestive tract is supremely finicky. Massive risk of internal infections, for starters. A family member had a piece of colon removed because of cancer, took over six months with antibiotics to recover.

[sktarq]

Also whhile we simplify it to the "the intestines" or even a couple major parts the system is majorly complex and a series of similar things rather than one long single process. Different parts of the GI tract have

Spoiler: rather different ph

Show

The intraluminal pH is rapidly changed from highly acid in the stomach to about pH 6 in the duodenum. The pH gradually increases in the small intestine from pH 6 to about pH 7.4 in the terminal ileum. The pH drops to 5.7 in the caecum, but again gradually increases, reaching pH 6.7 in the rectum

just to start. Also there is a lot we don't understand about how the gut functions in relation to the overall system. So there really isn't a place you could take out a chunk without crippling the system...

the stomach is just the simplest place to deal with things. and while gastric bands are now the norm they replaced staples in some early forms of the treatment...and in some cases the area that is today banded off would be surgically removed..and they found leaving it in was better it seems (actually looking for comparitor studies on this could be a good source in general). And as others have mentioned. It is the stomach not the intestines that key the "stop eating" responses to the brain and also the great benefit of making the surgery both much simpler to perform (especially laparoscopicly) and with a much lower chance of complications with bleeding into the gut, escape of GI bacteria into the abdomen and thus sepsis, etc and thus lower costs of insurance and more people choosing to take the surgery in the first place so there are also "market factors".

[Tvtyrant]

Having been morbidly obese, and from a family of morbidly obese people... My micronutrient intake was abysmal. Next to no fruits or vegetables, no variety in them at all, most of the food is some form of sugar and buttered up carb with sugar and buttered up cheap meat. Even if I ate potatoes I ate way too little actual potato and way too much stuff on top of it to get the kind of potassium they could have offered, and if I ate salad it was almost always lettuce instead of spinach, broccoli, etc.

If I got intestinal banding and didn't change diets I would have been severally malnourished.

I will also say that my stomach is physically larger then you can imagine, I have considered banding even though I already lost the weight just so I don't feel constantly hollow bellied. I think it would be a terrible mistake in practice, but not having to eat 3-5lbs of food a day to feel satisfied would be nice.

[Willie the Duck]

Beyond what others have stated, two factors spring to mind: --

• reversibility -- stomach banding is reversible, so if there are complications or the recipient is having negative consequences, it can be un-done
• nervous and immunological system -- the digestive track has it's own nerves, and is loci for parts of the nervous system. While the stomach is indeed part of that system, it doesn't seem to be as much of a keystone point for any of it. OTOH, cut out part of the intestines and everything downstream loses their nerve connection (and as sktarq points out, you probably wouldn't want to just lop off the last bit and call it a day).

If I got intestinal banding and didn't change diets I would have been severally malnourished.

I know you meant intestinal recession, but just following this to the logical conclusion, Intestinal banding would be a bad solution to the problem. It'd slow down transit through them, increasing the nutrient uptake. One of those nutrients would be water, so there'd be some serious constapatory/intestinal blockage issues.

[Tvtyrant]

Beyond what others have stated, two factors spring to mind: --

• reversibility -- stomach banding is reversible, so if there are complications or the recipient is having negative consequences, it can be un-done
• nervous and immunological system -- the digestive track has it's own nerves, and is loci for parts of the nervous system. While the stomach is indeed part of that system, it doesn't seem to be as much of a keystone point for any of it. OTOH, cut out part of the intestines and everything downstream loses their nerve connection (and as sktarq points out, you probably wouldn't want to just lop off the last bit and call it a day).

I know you meant intestinal recession, but just following this to the logical conclusion, Intestinal banding would be a bad solution to the problem. It'd slow down transit through them, increasing the nutrient uptake. One of those nutrients would be water, so there'd be some serious constapatory/intestinal blockage issues.

Depending on how much it slowed it down you would have to quit eating meat to prevent it rotting inside you...