Basically, gastroparesis means delayed gastric emptying.
Gastroparesis can lead to a host of symptoms. Bloating, nausea, stomach pain, vomiting, and acid reflux, a just a few of them.
I interviewed expert gastroenterologist Dr. Mark Noar, to find out about the causes, diagnosis and treatment of gastroparesis.
In a few sentences, what is gastroparesis?
Dr. Mark Noar: Gastroparesis means the stomach is emptying too slowly.
When I say the stomach is emptying slowly, I mean compared to numbers that we have from studies on people that we consider normal, with no symptoms.
How do you diagnose delayed gastric emptying?
We use a gastric emptying scan. This scan shows how quickly the stomach empties. You are given a test meal. It contains a standardized amount of calories, fat, and carbohydrates.
The scan shows the stomach’s fullness at certain time intervals after you eat the meal. It gives you a clear picture of how quickly or slowly your stomach is emptying.
What would a normal gastric emptying study look like?
Typically, by the second hour, we expect to see 50% or more of the food having emptied from the stomach.
After four hours, we expect there to be no more than 10% of the food remaining in the stomach.
So, at 2 hours the stomach should be about half empty. After 4 hours it should be nearly empty.
Why are those two values important?
Two hours is when you notice many of the symptoms of gastroparesis. They show up when people have retained more than 50% of the food.
There is another subset of patients who empty normally at two hours but have significant delays at four hours.
It is complex. It depends upon the type of gastroparesis you have, each of which have a very different potential cause and treatment.
How do you diagnose those gastroparesis subgroups?
If we’re looking purely at the gastric emptying scan, then the first two subgroups are going to be [diagnosed by the number of] percent emptying at two hours and percent emptying at four hours.
Then there are subsets based on the cause of gastroparesis. That is where the electrogastrogram, or EGG, becomes essential. The EGG helps to diagnose problems with gastric motility [see interview about gastric motility].
Your stomach might empty normally, but you may still be symptomatic because your stomach is not contracting normally. And that’s an important distinction to understand. It’s not always about whether the gastric emptying scan is normal or abnormal. It’s about whether you have symptoms. Even more important: can we tie those symptoms to an abnormal rhythm or electrical frequency in the stomach?
What does the treatment for gastroparesis look like?
It is extremely dependent on what is causing the gastroparesis. This is where the electrogastrogram plays a crucial role, as it will tell us where your problem comes from.
Can you give me some examples of typical patients?
If we take 100 people with gastroparesis, 25 of them would have functional outlet obstruction, based on the electrogastrogram. In those patients, you do a balloon dilation, and the gastroparesis may be cured 93% of the time.
For the other 75 patients, we look at the quality of the ICC (interstitial cells of Cajal), which are essential cells for gastric motility. The ICCs are the transmitting cells that sit between the nerves and the muscle [see interview about gastric motility].
About 25 of the original group of 100 patients will have damaged ICCs. If the ICCs are in poor shape, that’s usually a microcirculatory problem [typically diabetes], so we offer medication to improve the circulation. Nitrous oxide is an example of a drug that we would give. It improves the circulation and may allow the ICCs to regrow. They would return to normal, and the gastroparesis should improve.
The other 50 patients have properly functioning ICCs and are not obstructed functionally, but they have some other type of abnormal gastric motility. Then you have to check whether those patients have significant reflux. If they do, you can cure the gastroparesis often by fixing the lower esophageal sphincter that has become too loose.
That’s it for this part of the interview.
The key take-away: untreated gastroparesis can lead to acid reflux.
Read the next part of my interview with Dr. Mark Noar to find out more about the connection between gastroparesis and reflux.