The Insider's View of Stomach pH

The term pH, which means "potential hydrogen," represents a scale for the relative acidity or alkalinity of a solution. Acidity is measured as a pH of 0.1 to 6.9, and alkalinity as pH of 7.1 to 14; a pH of 7.0 is considered neutral. The numbers refer to how many hydrogen atoms are present compared to an ideal or standard solution.

Normally, blood is slightly alkaline, at 7.35 to 7.45; urine pH can range from 4.8 to 7.5, although normal is closer to 7.0.
An effective way to determine the pH in the stomach is the Heidelberg pH capsule System. According to its manufacturer, this “tubeless gastric analysis" is a way of showing abnormal conditions of acidity or alkalinity in the stomach or small intestines.

A miniature electronic transmitter is put inside a small capsule made of polyacrylate (which is inert and indigestible). The patient swallows this; once in the stomach, the capsule transmits, by radio signals, continuous and/or changing values for the pH of that area.

The capsule is active for about 22 hours after ingestion. These recordings of the pH fluctuations are displayed in graph form, called a gastrogram. The stomach's pH can be challenged by introducing an alka-linizing drink such as sodium bicarbonate; the gastrointestinal system's response to this challenge offers valuable information about its health.

The technique was developed in the 1950s by German researcher Hans G. Noller, M.D., professor of pediatrics at the University of Heidelberg. Dr. Noller sought an alternative to the invasive, uncomfort­able stomach tube procedure commonly used by gastroenterologists to assess stomach and small-intestine function. Since its invention, over 200 scientific studies have reported on the Heidelberg pH cap­sule's application for a variety of gastroin­testinal conditions.