PNEUMATOSIS CYSTOIDES INTESTINALS AND HIGH BREATH H-2 EXCRETION - INSIGHTS INTO THE ROLE OF H-2 IN THIS CONDITION

Patients with pneumatosis cystoides intestinalis have been reported to excrete excessive H-2 because of a lack of H-2-consuming intestinal bacteria. This study describes a patient with bacterial overgrowth and pneumatosis of the small intestine whose colonic flora avidly consumed H-2 but whose small bowel flora produced but did not consume H-2. There is no commonly accepted mechanism whereby excessive luminal H-2 causes intramural gas. An explanation is proposed in which an initial, transitory source of intramural gas is distinguished from the mechanism that results in the persistence of the gas. Independent of the initial source of gas, rapid diffusion of H-2 from the lumen into an intramural gas bubble would cause N-2, O-2, and CO2 to diffuse from the blood into the bubble, As a result, the bubble would expand and then persist indefinitely as long as H-2 continued to diffuse from the lumen to the intramural gas collection.