Other Gastrointestinal Testing and Therapeutic Procedures

Breath tests typically involve ingestion of a substrate that is then metabolized by gastrointestinal bacteria or digestive enzymes. The metabolites of the ingested substrate are then measured in the exhaled breath of the patient.

Various breath tests help diagnose conditions such as

• Helicobacter pylori infection

• Carbohydrate intolerance: Hydrogen (H2) breath test (lactose or fructose breath test)

• Small intestinal bacterial overgrowth

Wireless motility capsule involves an ingestible device that continuously measures the pressure and pH of the intraluminal environment as the device travels through the gastrointestinal tract. It is used to measure transit time, pressure profile, and motility of the entire gastrointestinal tract and of individual regions (stomach, small intestine, colon). This device can help assess gastric emptying as well as small-bowel and colonic transit in patients presenting with symptoms suggestive of dysmotility.

Electrical stimulation of gastrointestinal nerves can be used to treat a variety of gastrointestinal disorders of motility.

Low parasympathetic tone is thought to be the cause of gastrointestinal dysmotility. Neuromodulation increases parasympathetic tone thereby improving peristalsis and gastrointestinal transit of food and gas. Furthermore, neuromodulation may affect visceral and central pain pathways thereby targeting some of the pathophysiologic mechanisms believed to cause disorders such as irritable bowel syndrome (IBS).

Gastric electrical stimulation has been used in patients with diabetic or idiopathic gastroparesis for the treatment of refractory symptoms, particularly nausea and vomiting. Gastric electrical stimulation is achieved through the surgical placement of electrical nodes into the stomach. Use of gastric electrical stimulation is not widespread and is only available at specialized centers for select patients.

Sacral stimulators are used to treat fecal incontinence. Stimulation of the sacral nerve increases rectal tone and results in fewer episodes of incontinence. Sacral stimulators are initially placed externally to determine efficacy and then implanted through a minimally invasive procedure, typically by a surgeon.

Vagus nerve stimulation, acupuncture, and, more recently, transcutaneous electrical neural stimulation are being explored to treat various gastrointestinal conditions, including IBS with constipation.