Evaluation of an extremely flatulent patient: case report and proposed diagnostic and therapeutic approach.

We recently encountered a patient with severe flatulence who previously had been subjected to innumerable diagnostic tests and ineffective therapies based on the belief that his rectal gas was produced in the colon. Analysis of three flatus samples demonstrated that nitrogen (N2) was the predominant flatus gas whereas the three gases produced in the gut (CO2, H2 [hydrogen], and CH4 [methane]) comprised <16% of rectal gas. This result plus a series of other diagnostic tests clearly indicated that the patient's flatus was derived almost entirely from swallowed air. Based on this case, the present report summarizes available data on excessive flatulence and suggests a rational approach to the patient complaining of this problem. Particular emphasis is placed upon a sequential strategy consisting of: 1) a count of flatus passages to determine if the subject truly is abnormal (normal: <20 passages/day); 2) an analysis of flatus to determine if the flatus originates from swallowed air (predominantly nitrogen) or intraluminal production (predominantly CO2, H2, and CH4); and 3) treatment based upon the origin of the rectal gas.