Adverse responses include difficulty swallowing, chest pain, vomiting, and nausea. Contraindications that would advise against use of the device are patients who are or may be allergic to titanium, stainless steel, nickel, or ferrous iron materials. A warning advises that the device should not be used by patients who could be exposed to, or undergo, magnetic resonance imaging (MRI) because of serious injury to the patient and damage to the device.In those with symptoms that do not improve with PPIs surgery known as transoral incisionless fundoplication may help. Benefits may last for up to six years. Special populations
Pregnancy
GERD is a common condition that develops during pregnancy, but usually resolves after delivery. The severity of symptoms tend to increase throughout the pregnancy. In pregnancy, dietary modifications and lifestyle changes may be attempted, but often have little effect. Some lifestyle changes that can be implemented are elevating the head of the bed, eating small portions of food at regularly scheduled intervals, reduce fluid intake with a meal, avoid eating 3 hours before bedtime, and refrain from lying down after eating. Calcium-based antacids are recommended if these changes are not effective, aluminum- and magnesium hydroxide -based antacids are also safe. Antacids that contain sodium bicarbonate or magnesium trisilicate should be avoided in pregnancy. Sucralfate has been studied in pregnancy and proven to be safe  as is ranitidine and PPIs.
It is recommended when people either do not respond well to treatment or have alarm symptoms, including dysphagia, anemia, blood in the stool (detected chemically), wheezing, weight loss, or voice changes. Some physicians advocate either once-in-a-lifetime or 5- to 10-yearly endoscopy for people with longstanding GERD, to evaluate the possible presence of dysplasia or Barretts esophagus.Biopsies performed during gastroscopy may show:

Edema and basal hyperplasia (nonspecific inflammatory changes)
Lymphocytic inflammation (nonspecific)
Neutrophilic inflammation (usually due to reflux or Helicobacter gastritis)
Eosinophilic inflammation (usually due to reflux): The presence of intraepithelial eosinophils may suggest a diagnosis of eosinophilic esophagitis (EE) if eosinophils are present in high enough numbers. Less than 20 eosinophils per high-power microscopic field in the distal esophagus, in the presence of other histologic features of GERD, is more consistent with GERD than EE. Goblet cell intestinal metaplasia or Barretts esophagus
Elongation of the papillae
Thinning of the squamous cell layer
Dysplasia
CarcinomaReflux changes that are not erosive in nature lead to "nonerosive reflux disease". Severity
Severity may be documented with the Johnson-DeMeesters scoring system:
0 - None
1 - Minimal - occasional episodes
2 - Moderate - medical therapy visits
3 - Severe - interference with daily activities

Differential diagnosis
Other causes of chest pain such as heart disease should be ruled out before making the diagnosis. Another kind of acid reflux, which causes respiratory and laryngeal signs and symptoms, is called laryngopharyngeal reflux (LPR) or "extraesophageal reflux disease" (EERD). Unlike GERD, LPR rarely produces heartburn, and is sometimes called silent reflux.