Effects of Weight Loss Surgery on Digestion and Nutrient Absorption
All kinds of weight loss surgery change your digestive tract, or gastrointestinal tract (GI tract), in one or more ways. Understanding normal digestion and nutrient absorption is helpful for understanding the changes that occur with each of the various weight loss surgeries
Digestion occurs when your body breaks food down into smaller components. Digestion begins in your mouth, when you chew, and continues as digestive enzymes mix with food and break it down further in your stomach and intestines. Digestion makes nutrients (proteins, fats, carbohydrates, vitamins and minerals) available to for your body to absorb.
Absorption is when your body takes nutrients from the GI tract and brings them into your body. Weight loss surgery can interfere with digestion and/or absorption to promote weight loss.
Digestion, Absorption, the GI Tract and Weight Loss Surgery
This table describes the passage of food in the GI tract from the beginning to end. It also describes how weight loss surgery can change the normal process.
| Organ/Location | Process(es) | Possible Effect(s) of Weight Loss Surgery |
|---|---|---|
| Mouth |
|
No direct effects, but all weight loss surgery diets require slower eating and thorough chewing. This can lead to you to eat less. |
| Esophagus | Food passes from mouth to stomach | No direct effects, but all weight loss surgeries shrink your stomach pouch. Overeating overfills the pouch and can cause heartburn and esophagitis. |
| Stomach |
|
|
| Small intestine |
|
|
| Large intestine |
|
Unchanged by bariatric surgery |
| Rectum and anus | Excretion of waste as feces | Unchanged by bariatric surgery |