Gastroccult: Two Tests in One. Gastroccult is the only test designed specifically for gastric occult blood and pH testing. Gastroccult has a convenient pH comparison chart on the test card. The pH scale provides the entire clinically relevant range for monitoring antacid prophylaxis. With Gastroccult, you can be confident because Gastroccult is the only accurate way to detect blood in gastric specimens or vomitus. When used with gastric specimens, fecal occult blood tests do not provide reliable results. Gastroccult can reliably verify low levels of blood in samples containing bile. No need to rely on a subjective visual inspection.