Small intestinal bacterial overgrowth in patients with lower gastrointestinal symptoms and a history of previous abdominal surgery.

BACKGROUND

The small intestinal bacterial overgrowth (SIBO) breath test has had positive results in 84% of patients with irritable bowel syndrome vs 20% of controls. We hypothesized that SIBO would be more prevalent in patients with symptoms consistent with irritable bowel syndrome who have undergone previous abdominal surgery.

OBJECTIVE

To identify causative factors for SIBO.

DESIGN

Retrospective review.

SETTING

Tertiary colorectal surgery clinic.

MAIN OUTCOME MEASURE: Result of SIBO breath test.

RESULTS

We identified 77 patients whose differential diagnosis included SIBO from January 1, 2005, to December 31, 2007; 18 were excluded because of noncompliance with testing and 2 because of a decision to treat SIBO without formal testing. Symptoms were chronic abdominal pain in 30 patients (53%), bloating in 25 (44%), constipation in 37 (65%), and diarrhea in 7 (12%). Mean (SD) symptom duration was 45 (22) months. Of the 57 patients enrolled in this study, 45 (79%) tested positive for SIBO and 37 (82%) of those had a history of surgery, whereas 12 (21%) tested negative for SIBO and 9 (75%) of those had a history of surgery. Of the 36 SIBO-positive patients with a history of abdominal surgery (mean number of procedures, 2), the surgery locations were as follows: female reproductive organs, 23 (64%); hindgut, 15 (42%); foregut, 8 (22%); and midgut, 6 (17%). Open surgery alone was performed in 32 patients (56%) vs laparoscopic surgery in 7 (12%). Both open and laparoscopic procedures had been performed in 6 patients (11%). Four patients (7%) had a history of small intestinal obstruction. The mean age of SIBO-positive patients was higher than that of SIBO-negative patients (57 vs 44 years; P < .01). Analysis did not reveal any clinically significant independent factor associated with SIBO.

CONCLUSION

Physicians should consider SIBO in the differential diagnosis of patients with normal anatomic findings and chronic lower gastrointestinal complaints.