What is delayed gastric emptying?
A slow stomach is a common term that is used to describe delayed gastric emptying. This means that the contents of the stomach are not released into the duodenum at a normal rate. It may be related to a disorder with the :
- stomach nerves and neurotransmitters
- digestive hormones
- smooth muscle of the stomach wall
- mechanical obstruction
Gastroparesis is delayed gastric emptying with no mechanical obstruction to the flow of gastric contents. Gastric outlet obstruction on the other hand is when there is a mechanical obstruction to the flow of gastric contents out of the stomach.
Causes of Slow Stomach
It is important to understand the process of gastric emptying and that factors that promote and inhibit it.
- Normal Gastric Emptying
- What is gastric emptying?
- How does gastric emptying work?
- What promotes and inhibits gastric emptying?
Causes of gastroparesis include :
- Diabetic neuropathy
- Anorexia nervosa and bulimia (refer to Effects of Eating Disorders)
- GERD (gastroesophageal reflux disease)
- Amyloidosis of the gastric musculature
- Parkinson’s disease
- Viral infections
- Surgery affecting the vagus nerve
- Calcium channel antagonists
- Anticholinergics like tricyclic antidepressants and phenothiazines
Gastric Outlet Obstruction
The mechanical obstruction may lie in the duodenum or within the pyloric channel (intrinsic). Any mass outside of the organs surrounding the stomach and duodenum may also cause an obstruction to the flow of chyme (extrinsic).
Causes of gastric outlet obstruction include :
- Pyloric edema due to gastritis or peptic ulcer
- Pyloric stenosis
- Fibrotic stricture of duodenal ulcer
- Adult hypertrophic pyloric stenosis
- Gastric polyps
- bile ducts (cholangiocarcinoma)
- Congenital duodenal webs
- Pancreatic pseudocysts
- Gallstone obstruction
Signs and Symptoms
The signs and symptoms of delayed gastric emptying, whether due to a mechanical obstruction (gastric outlet obstruction) or stomach nerve and muscle disorders (gastroparesis), may be of a sudden or gradual onset.
Any disruption in normal gastric emptying causes a build up of undigested food, partially digested food particles, and chyme. Further eating or drinking may cause a backflow resulting in nausea and vomiting. The fairly ‘stagnant’ gastric contents are prone to bacterial overgrowth within the stomach resulting in fermentation of food. Partially digested food can coalesce and harden into solid masses known as bezoars. This can cause further obstruction of the pyloric canal.
Gastroparesis and gastric outlet obstruction are usually of a gradual onset. However, gastroparesis due to vagal nerve damage after surgery may result in the sudden onset of the signs and symptoms of delayed gastric emptying. The most severe symptoms may be noted in complete gastric outlet obstruction which is rare unless the condition has been left untreated for a prolonged period of time.
Since gastroparesis and gastric outlet obstruction occur secondary to an underlying disorder, the clinical presentation may vary depending on the cause.
The common signs and symptoms of delayed gastric emptying includes :
- Vomiting – severe projectile vomiting may indicate a complete obstruction
- Abdominal distension
- Bloating (feeling of fullness even after a small meal or few bites of food)
- Early satiety
- Heartburn (gastroesophageal reflux, acid reflux)
- Excessive belching
- Lack of appetite
- Unintentional weight loss
- Gastric pain – upper middle abdominal pain, left upper abdominal pain
- Fluctuation in blood glucose levels – high and low blood sugar
- Stomach cramps
- Signs of vitamin deficiencies as a result of malabsorption
- Offensive odor of the breath (halitosis) and burps (sulfur burps) as a result of bacterial overgrowth
- Altered bowel movements may be noticed, particularly constipation
- Dehydration, especially if there is constant vomiting