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Small Intestinal Bacterial Overgrowth (SIBO) and Fungal Overgrowth (SIFO): A Frequent and Unrecognized Complication of Colectomy: ACG Category Award: Presidential Poster


Abdulla, Hamza M. MD1; Yu, Siegfried MD2; Rattanakovit, Kulthep3; Badger, Collier3; Rao, Satish MD4

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American Journal of Gastroenterology: October 2015 - Volume 110 - Issue - p S995
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Introduction: Following subtotal colectomy, approximately 40% of patients report abdominal pain and diarrhea, and this is associated with poor quality of life. Its cause is unknown and many are labeled as IBS. In a pilot study, we observed a high incidence of bacterial overgrowth in post-colectomy patients. Our aim was to determine the prevalence of SIBO/SIFO in patients with unexplained GI symptoms following colectomy (> 1 year).

Methods: Patients seen between January 2012 to March 2015 with chronic GI complaints and a history of colectomy and negative GI evaluation (endoscopy, blood tests, CT scan) other than post-op changes were assessed and underwent testing for SIBO with either 75 g glucose breath test (GBT) and/or distal duodenal aspiration (DDA). The DDA was performed using aseptic technique with a sterile 6F Liguory nasobiliary catheter, and cultures were obtained for aerobic, anaerobic, and fungal organisms. Bacterial concentrations≥103 cfu/mL was defined as SIBO positive.

Results: 50 patients (F/M =41/9; mean age 52.32 years) with prior colectomy were assessed. Of these, 48/50 patients underwent GBT alone, 33 underwent GBT and DDA, and 2 underwent DDA alone. We found that 31/50 patients(62%) had SIBO. 16 subjects with SIBO had aerobic flora (streptococcus and klebsiella spp.), and 11 had anaerobic flora (bacteroides veillonella, and peptostreptococcus spp). In this subgroup 12/31(39%) had concurrent SIFO and 2/50(4%) had SIFO alone—all grew candida. Abdominal pain, gas, bloating, diarrhea, and nausea are common and severe (table1). Patients with SIBO/SIFO had greater symptoms than those without. The indication for subtotal colectomy was constipation(36%), diverticular disease(8%), bowel obstruction(8%), colorectal carcinoma(8%), polyps(6%), other (26%), or not documented (8%). The prevalence of SIBO in patients with history of constipation was 10/18(56%) compared to 22/32(69%) in patients without constipation.

Conclusion: Overall 62% of patients with previous colectomy and chronic GI symptoms had undiagnosed SIBO and 39% had concurrent SIFO. SIBO and SIFO are important, frequent, and unrecognized complications following colectomy that explain their persistent gas, bloating, and pain. This occurs either because of small intestinal colonization by colonic flora by translocation through a widely patent ileocolonic anastomosis and/or dysmotility. SIBO/SIFO should be identified and treated in patients with persistent GI symptoms after colectomy, and not mislabeled as IBS.

Table 1
Table 1:
Symptom prevalence and severity in patients with SIBO, Mixed SIBO and SIFO, SIFO and no overgrowth
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