Gastroparesis

Gastroparesis, also known as delayed gastric emptying, is a condition characterised by weak muscular contractions (peristalsis) of the stomach, leading to prolonged retention of food and liquid in the stomach.

This can result in irregular nutrient absorption, inadequate nutrition, and poor glycaemic control. The primary cause is often autonomic neuropathy of the vagus nerve, with diabetes mellitus being a significant risk factor.

Signs and Symptoms

Common symptoms of gastroparesis include nausea, vomiting, abdominal pain, early satiety, abdominal bloating, and heartburn. Symptoms often worsen after consuming fatty foods and indigestible solids like leafy vegetables. Nausea is the most frequently reported symptom, occurring in up to 96% of patients. Vomiting may involve retching and forceful expulsion of gastric contents.

Postprandial fullness is a common complaint, with patients feeling an unpleasant sense of fullness after eating. Early satiety, the sensation of fullness soon after starting a meal, is also prevalent. Abdominal pain, often described as postprandial epigastric pain, affects about 90% of patients and can vary from localised to diffuse.

Complications

Gastroparesis can lead to several complications, including malnutrition, weight loss, vitamin deficiencies, and dehydration. It can also result in bezoar formation, where large masses of foreign substances and food get trapped in the GI tract, and small intestine bacterial overgrowth (SIBO). Poor glycaemic control, aspiration, and abnormalities in fluid and electrolyte balance are other potential issues.

Causes

Transient gastroparesis can occur due to acute illness, certain medications, or abnormal eating patterns. Chronic gastroparesis is frequently caused by autonomic neuropathy, often linked to diabetes mellitus. Other causes include chemotherapy-induced neuropathy, vagus nerve damage from abdominal surgery, and infections.

Idiopathic gastroparesis, where no known cause is identified, accounts for a third of all chronic cases. The condition disproportionately affects women, possibly due to hormonal factors or inherently slower gastric emptying times.

Diagnosis

Gastroparesis is suspected in patients presenting with symptoms like abdominal pain, nausea, vomiting, or bloating, especially postprandially. Diagnosis typically involves ruling out other conditions via upper endoscopy before conducting specific tests for gastroparesis.

The gold standard for diagnosis is gastric emptying scintigraphy (GES), which measures the rate of gastric emptying using a radiotracer-bound meal. Other diagnostic methods include the stable isotope breath test, wireless motility capsule (WMC), and antroduodenal manometry. Transabdominal ultrasonography and MRI are also used in research settings.

Treatment

Treatment for gastroparesis includes dietary modifications, medications, and surgical interventions. Dietary changes involve consuming low-fibre, low-fat meals in smaller, more frequent portions. Metoclopramide and domperidone are commonly prescribed medications that enhance gastric emptying and reduce nausea and vomiting. Erythromycin may offer temporary relief. Mirtazapine, an antidepressant, has shown effectiveness due to its antiemetic and appetite-stimulating properties.

For refractory cases, gastric electrical stimulation (GES) may be used, where a medical device is implanted to stimulate stomach muscles. Other surgical options include pyloromyotomy, which widens the gastric outlet, and vertical sleeve gastrectomy, particularly for obese patients. In cases of post-infectious gastroparesis, early diagnosis and treatment are very important, as symptoms can persist for several months before proper identification.

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Self-assessment MCQs (single best answer)

What is the primary cause of gastroparesis?

Which symptom is most frequently reported by patients with gastroparesis?

Which diagnostic method is considered the gold standard for diagnosing gastroparesis?

What dietary modification is recommended for patients with gastroparesis?

What medication is commonly prescribed to enhance gastric emptying and reduce nausea and vomiting in gastroparesis patients?

Which gender is disproportionately affected by gastroparesis?

What is a potential complication of gastroparesis?

In addition to metoclopramide, which other medication is noted for its effectiveness due to antiemetic and appetite-stimulating properties?

What is a common cause of transient gastroparesis?

Which surgical option involves the implantation of a medical device to stimulate stomach muscles for refractory gastroparesis cases?