Functional Gastrointestinal Disorders

Functional gastrointestinal disorders (FGID) are a diagnostic category defined by the only presentation of some symptoms and characterized by the absence of an evident pathogenetic substrate.
All these pathologies are characterized by abdominal pain and altered bowel functionality.

Gastroesophageal reflux disease (GERD) is a chronic symptom of mucosal damage caused by stomach acid coming up from the stomach into the esophagus. GERD is usually caused by changes in the barrier between the stomach and the esophagus, including abnormal relaxation of the lower esophageal sphincter, which normally holds the top of the stomach closed, impaired expulsion of gastric reflux from the esophagus, or a hiatal hernia. These changes may be permanent or temporary.

GERD is caused by a failure of the lower esophageal sphincter. In healthy patients, the “Angle of His”—the angle at which the esophagus enters the stomach—creates a valve that prevents duodenal bile, enzymes, and stomach acid from travelling back into the esophagus where they can cause burning and inflammation of sensitive esophageal tissue.

Treatment is typically via lifestyle changes and medications. Surgery may be an option in those who do not improve.

Dyspepsia, also known as indigestion, is a condition of impaired digestion. It is a medical condition characterized by chronic or recurrent pain in the upper abdomen, upper abdominal fullness and feeling full earlier than expected when eating. It can be accompanied by bloating, belching, nausea, or heartburn. Dyspepsia is a common problem and is frequently caused by gastroesophageal reflux disease (GERD) or gastritis.

Irritable bowel syndrome (IBS, or spastic colon) is a symptom-based diagnosis characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits. As a functional gastrointestinal disorder (FGID), IBS has no known organic cause. Diarrhea or constipation may predominate, or they may alternate. A diagnosis of IBS can be made on the basis of symptoms alone, in the absence of alarm features such as age of onset greater than 50 years, weight loss, gross hematochezia, systemic signs of infection or colitis, or family history of inflammatory bowel disease. Onset of IBS is more likely to occur after an infection, or a stressful life event, but varies little with age.

Although no cure for IBS is known, treatments to attempt to relieve symptoms exist, including dietary adjustments, medication, and psychological interventions. Patient education and good doctor-patient relationships are also important. Several conditions may present themselves as IBS, including coeliac disease, fructose malabsorption, mild infections, parasitic infections etc. The exact cause of IBS is unknown. The most common theory is that IBS is a disorder of the interaction between the brain and the gastrointestinal tract. For at least some individuals with IBS, abnormalities in the gut flora occur, and it has been theorised that these abnormalities results in inflammation and altered bowel function.