Surgery: Understanding The Normal Digestive Process
To the right is a graphic description of
how the digestive process looks prior to weight loss
surgery. (Click the picture to view a larger version in a
Normally, as food moves along the digestive tract, digestive
juices and enzymes digest and absorb calories and nutrients.
After we chew and swallow our food, it moves down the esophagus
to the stomach, where a strong acid continues the digestive
process. The stomach can hold about 3 pints of food at one
When the stomach contents move to the duodenum, the first
segment of the small intestine, bile and pancreatic juice speed
up digestion. Most of the iron and calcium in the foods we eat
is absorbed in the duodenum.
The jejunum and ileum, the remaining two segments of the
nearly 20 feet of small intestine, complete the absorption of
almost all calories and nutrients. The food particles that
cannot be digested in the small intestine are stored in the
large intestine until eliminated.
Gastrointestinal Surgery - Also Called Bariatric Surgery -
Promote Weight Loss?
Gastrointestinal surgery for obesity, also called bariatric
surgery, alters the digestive process. The operations promote
weight loss by closing off parts of the stomach to make it
smaller. Operations that only reduce stomach size are known as
“restrictive operations” because they restrict the amount of
food the stomach can hold.
Some operations combine stomach restriction with a partial
bypass of the small intestine. These procedures create a direct
connection from the stomach to the lower segment of the small
intestine, literally bypassing portions of the digestive tract
that absorb calories and nutrients. These are known as
What Are the Weight
Loss Surgery Options?
There are several types of restrictive and malabsorptive
operations. Each one carries its own benefits and risks.
Restrictive Operations For Weight Loss
Restrictive operations serve only to restrict food intake
and do not interfere with the normal digestive process. To
perform the surgery, doctors create a small pouch at the top of
the stomach where food enters from the esophagus. Initially,
the pouch holds about 1 ounce of food and later expands to 2-3
ounces. The lower outlet of the pouch usually has a diameter of
only about ¾ inch. This small outlet delays the emptying of
food from the pouch and causes a feeling of fullness.
As a result of this surgery, most people lose the ability to
eat large amounts of food at one time. After an operation, the
person usually can eat only ¾ to 1 cup of food without
discomfort or nausea. Also, food has to be well chewed. On the
next page there are some pictures and further details on this
type of weight-loss surgery.
Malabsorptive Operations For Weight
Malabsorptive operations are the most common
gastrointestinal surgeries for weight loss. They restrict both
food intake and the amount of calories and nutrients the body
absorbs. You will find pictures and further details on the next