Participants reported similar increases in bloating with the nonfermentable fiber methylcellulose. The bloating associated with psyllium and methylcellulose presumably reflects the increased fecal mass that results from the water-holding capacity of fiber. It should be stressed that we evaluated subjective responses to dietary supplements that differed in taste and appearance. In addition, potential variables such as diet, air swallowing, and the colonic flora could not be controlled. The occurrence of more than 20 flatus passages per day indicates excessive rectal gas, which in turn usually means that excessive fermentable substrate is reaching the colonic flora.
Treatment includes limiting the quantity of fermentable material that reaches the colon.
In contrast, persons who report abdominal bloating are probably not producing excessive gas. Studies to visualize the gastrointestinal tract are rarely useful in such patients. Therapy should consist of treating of the underlying irritable bowel syndrome. H2 excretion after ingestion of complex carbohydrates. Studies of a flatulent patient.