Dumping syndrome is a condition in which food moves rapidly from the stomach into the small intestines. This is almost always caused by eating high-fat, high-sugar foods, particularly after the gastric bypass procedure. However, dumping syndrome can occur in anyone that has had stomach or esophageal surgery.
Roughly 20 to 50% of gastric bypass patients will experience dumping syndrome at some point. There are two forms of dumping syndrome–early dumping and late dumping. Early dumping occurs within 10 to 30 minutes of eating, whereas late dumping can begin within 1 to 3 hours of eating.
Early dumping syndrome is believed to be a result of liquid from the stomach rapidly entering the small intestines, causing an increase in volume within the small bowel. This rapid shift in the fluid can cause abdominal cramps, nausea, diarrhea, and increased heart rate.
On the contrary, the exact causes of late dumping syndrome are unknown; however, it is believed to be associated with hypoglycemia. "It is proposed that the rapid absorption of carbohydrates exaggerates the glucose-mediated insulin response." Early dumping syndrome has a higher incidence rate compared to late dumping syndrome.
Dumping syndrome has gotten the nickname "impending sensation of doom" because of the severity and uncomfortability of the symptoms. Patients who experience early dumping syndrome will experience symptoms that include:
Symptoms characteristic of late dumping syndrome include:
When a patient has the gastric bypass procedure, a portion of their stomach is removed, and a new connection is made between the new stomach and the small bowel. In normal anatomy, patients have a muscle at the bottom of the stomach that regulates how much food to empty into the small intestines; this muscle is called the pylorus. However, after the gastric bypass, the pylorus is removed. The new connection between the stomach and small intestines is now man-made, which allows stomach contents to flow more freely into the small intestines.
Patients who have had the gastric sleeve or the duodenal switch are less likely to experience dumping syndrome because we do not remove the pylorus in those operations.
In normal anatomy, when an individual eats a high-carbohydrate meal, the stomach can read the sugar content and excrete the appropriate amount of gastric juices to dilute the food before sending it to the small intestines. This allows your body to absorb that high-sugar meal over time and better regulate how much insulin to produce to manage your blood sugar levels.
In patients who have had the gastric bypass procedure, that same high-carbohydrate meal will flow rapidly from the stomach to the small intestines, giving little to no time for the gastric juices to break down the food. As the highly concentrated, sugary food travels into the small intestines, the body recognizes that it needs to dilute this sugar with fluid. That fluid has to come from somewhere, so generally, the fluid comes from our intravascular space, and in doing so, this is going to lower your blood pressure. This explains why one side effect of dumping syndrome is dizziness or lightheadedness.
The other thing that occurs in post-op patients that eat a high-carbohydrate meal is an increase in insulin production which can cause a blood sugar crash. The lining of the intestines will recognize this high-sugar food and temporarily tell the body to increase insulin production. Despite this increase in insulin, not all the sugar gets absorbed, so now you have more circulating insulin, causing cause low blood sugar, making you feel weak, clammy, nauseous, and like your heart is racing.
Although dumping syndrome has a negative reputation, it can be considered a good thing because it will prevent you from overindulging in high-carbohydrate foods if you are aware of the symptoms that could follow.
