Gastroparesis (gastro- from Ancient Greek γαστήρ - gaster, "stomach"; and -paresis, πάρεσις - "partial paralysis"), also called delayed gastric emptying, is a medical disorder consisting of weak muscular contractions (peristalsis) of the stomach, resulting in food and liquid remaining in the stomach for a prolonged period of time. Stomach contents thus exit more slowly into the duodenum of the digestive tract. This can result in irregular absorption of nutrients, inadequate nutrition, and poor glycemic control.Symptoms include nausea, vomiting, abdominal pain, feeling full soon after beginning to eat (early satiety), abdominal bloating, and heartburn. The most common known mechanism is autonomic neuropathy of the nerve which innervates the stomach: the vagus nerve. Uncontrolled diabetes mellitus is a major cause of this nerve damage; other causes include post-infectious and trauma to the vagus nerve. Diagnosis is via one or more of the following: barium swallow X-ray, barium beefsteak meal, radioisotope gastric-emptying scan, gastric manometry, and esophagogastroduodenoscopy (EGD). Complications include malnutrition, fatigue, weight loss, vitamin deficiencies, intestinal obstruction due to bezoars, and  small intestine bacterial overgrowth. Treatment includes dietary modifications, medications to stimulate gastric emptying, medications to reduce vomiting, and surgical approaches.
This is due to its antiemetic and appetite stimulant properties. Mirtazapine acts on the same serotonin receptor (5-HT3) as does the popular anti-emetic ondansetron. Camicinal is a motilin agonist for the treatment of gastroparesis. In specific cases where treatment of chronic nausea and vomiting proves resistant to drugs, implantable gastric stimulation may be utilized. A medical device is implanted that applies neurostimulation to the muscles of the lower stomach to reduce the symptoms. This is only done in refractory cases that have failed all medical management (usually at least two years of treatment). Medically refractory gastroparesis may also be treated with a pyloromyotomy, which widens the gastric outlet by cutting the circular pylorus muscle. This can be done laparoscopically or endoscopically. Vertical sleeve gastrectomy, a procedure in which a part or all of the affected portion of the stomach is removed, has been shown to have some success in the treatment of gastroparesis in obese patients, even curing it in some instances. Further studies have been recommended due to the limited sample size of previous studies.In cases of postinfectious gastroparesis, patients have symptoms and go undiagnosed for an average of 3 weeks to 6 months before their illness is identified correctly and treatment begins. Prognosis
Post-infectious
Cases of post-infectious gastroparesis are self‐limiting, with recovery within 12 months of initial symptoms, although some cases last well over 2 years. In children, the duration tends to be shorter and the disease course milder than in adolescent and adults.