Table 1.
Parameter | Rifaximin 1200 mg/day (n = 162) | Rifaximin 2400 mg/day (n = 81) |
---|---|---|
Mean age (range), years | 58 (17–91) | 60 (17–91) |
Male:Female | 37:125 | 22:59 |
Race, n (%) | 43 (27) | 25 (31) |
White | 2 (1) | 1 (1) |
Black | 2 (1) | 0 (0) |
Asian | 4 (2) | 2 (2) |
Hispanic | 2 (1) | 2 (2) |
Other | 109 (67) | 51 (63) |
Not reported | 43 (27) | 25 (31) |
Mean duration of IBS (range), mo | 113.1 (6–480) | 128.4 (6–480) |
Disease subclass, n (%) | ||
IBS-D | 45 (28) | 24 (30) |
IBS-C | 33 (20) | 16 (20) |
IBS-M | 24 (15) | 11 (14) |
Not reported | 60 (37) | 30 (37) |
Lactulose breath test results, n (%)a | ||
Distal positiveb | 17 (10) | 10 (12) |
Hydrogen | 91 (56) | 44 (54) |
Methane | 32 (20) | 18 (22) |
Hydrogen and methane | 9 (6) | 4 (5) |
High baselinec | 23 (14) | 10 (12) |
Flatlined | 27 (17) | 15 (19) |
Negativee | 4 (2) | 1 (1) |
Inconclusive | 34 (21) | 18 (22) |
Notes:
Patients positive for hydrogen, methane, or both gases may have exhibited a high baseline or lacked a biphasic excretion pattern (distal positive);
patients who did not exhibit a biphasic pattern of gas excretion;
patients with ≥20 ppm before lactulose ingestion;
patients with a < 10 ppm increase in gas excretion within 120 minutes of lactulose ingestion;
patients with a < 10 ppm increase in gas excretion within 90 minutes of lactulose ingestion.
Abbreviations: IBS, irritable bowel syndrome; IBS-D, diarrhea-predominant irritable bowel syndrome; IBS-C, constipation-predominant irritable bowel syndrome; IBS-M, mixed-symptom irritable bowel syndrome.