Definition and Overview
Gastroparesis is a motility disorder that impairs the stomach’s ability to completely empty its contents. Also known as delayed gastric emptying or stomach paralysis, it occurs when the muscles in the stomach malfunction, which delays the movement of food from the stomach to the small intestine despite the lack of physical obstruction.
The digestive tract is made up of the oesophagus, stomach, and small and large intestines. When food enters the stomach through the mouth and oesophagus, it is mixed with gastric juices and churned by strong muscular contractions, propelling it through the digestive tract. In normal circumstances, the stomach is about 90% empty four hours after eating a meal. This process can be disrupted when the vagus nerve, which controls the stomach muscles and electrical signals to the stomach, is damaged by an illness or injury. The vagus nerve helps manage the complex processes in the digestive tract. It is responsible for expanding the stomach as food enters, breaking food into smaller particles, and emptying the stomach contents into the small intestine.
Gastroparesis can complicate diabetes as blood glucose levels rise when the food finally enters the small intestine. The condition also increases the risk of bacterial overgrowth and bezoars, or solid masses of undigested food that can potentially block the small intestine.
Causes of Condition
Gastroparesis is commonly the result of damage to the vagus nerve. A damaged vagus nerve can’t signal the muscles in the stomach to contract and push food into the small intestine so food remains in the stomach much longer than needed.
Damage to the vagus nerve can be caused by poorly controlled type 1 and type 2 diabetes, nervous system diseases such as multiple sclerosis and Parkinson’s disease, and abdominal or oesophageal surgery such as bariatric surgery and gastrectomy.
However, in many cases, gastroparesis causes are unknown (idiopathic gastroparesis).
Gastroparesis symptoms are:
Feeling full after eating a small meal
Erratic blood glucose levels
Spasm of the stomach wall
Vomiting, which could lead to dehydration
Malnutrition, as patients are unable to get enough nutrients from the food they eat
Who to See and Types of Treatments Available
Patients showing symptoms of gastroparesis can consult their family physician or a general practitioner who can make an initial assessment and refer them to a specialist, if needed.
To diagnose the condition and to rule out other gastrointestinal diseases that share the same symptoms, patients may have to undergo some or all of the following diagnostic tests:
A thorough physical exam
Upper gastrointestinal (GI) endoscopy - A procedure that uses a lighted endoscope to visualise the upper GI tract, which includes the oesophagus, stomach, and the first part of the small intestine. It can also be used to remove bezoars.
Ultrasound - An imaging test that often plays a definitive role in diagnosing GI problems. It uses high-frequency sound waves to show the movements of internal organs in real time. This non-invasive procedure, which uses a probe that is placed on the skin, can be used to rule out other medical conditions including pancreatitis and gallbladder disease.
Upper GI series - The patient must fast for eight hours prior to this procedure. During the test, the patient will stand in front of an x-ray machine and drink barium, which coats the small intestine. If images show that there is still food in the stomach eight hours after the last meal, gastroparesis is highly likely.
Gastric emptying scintigraphy - Performed to measure the rate of gastric emptying. For this procedure, the patient will eat a bland meal that contains a small amount of radioactive material, which can be monitored using an external camera. A gastroparesis diagnosis is confirmed if more than 10% of the meal is still in the stomach after four hours.
Gastroparesis cannot be cured but its symptoms can be managed to help improve patient’s quality of life. Treatment options for this condition include:
Dietary modifications - In many cases, changing eating habits can provide symptoms relief. The main goal is to ensure that less food enters the stomach each meal. Thus, doctors recommend eating six small meals instead of three larger ones throughout the day. Patients are also advised to chew food well and walk for two hours after a meal.
Medications - An FDA-approved gastroparesis medication is metoclopramide, which stimulates muscle contractions to move food through the stomach.
Gastric electrical stimulation - This gastroparesis treatment involves implanting a neurostimulator that sends mild electrical pulses to the smooth muscle and nerves of the lower stomach. The device can be implanted either laparoscopically or through traditional open surgery. While some patients experience symptoms relief immediately after the device has been implanted, some take months to see noticeable improvements in their condition.
Feeding tube - In severe cases wherein patients are unable to experience symptoms relief even after following a strict diet for gastroparesis or are unable to tolerate food or liquids, doctors recommend the use of feeding tubes, which can be passed through the nose or mouth or directly into the small intestine through the skin. The use of feeding tube can be either temporary or permanent. If used permanently, a J-tube (jejunal) is placed directly into the small intestine. The procedure can be performed laparoscopically, percutaneously, or via laparotomy.
The prognosis for patients with gastroparesis depends on the cause of the condition. Postsurgical and diabetic gastroparesis are chronic conditions and cannot be cured. Despite the absence of gastroparesis cure in such cases, symptoms can be relieved by combining nutritional support, strictly following gastroparesis diet, taking prescribed medications, and through strict glycemic control in patients with diabetes.
Feldman M, et al. Gastric neuromuscular function and neuromuscular disorders. In: Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management. 10th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. http://www.clinicalkey.com.
Clinical guideline: Management of gastroparesis. Bethesda, Md.: American College of Gastroenterology. http://gi.org/guideline/management-of-gastroparesis/.
Gastroparesis. The National Digestive Diseases Information Clearinghouse. https://www.niddk.nih.gov/health-information/health-topics/digestive-diseases/gastroparesis/Pages/facts.aspx.