Levothyroxine therapy and impaired clearance are the strongest contributors to small intestinal bacterial overgrowth: Results of a retrospective cohort study

Table 3 Impaired clearance

	SIBO		Non-SIBO		χ2 test	OR	RR
	n = 175	%	n = 1634	%	P value
Any abdominal surgery	51	29.1	487	29.8	0.466	-	-
Obstetric surgery	2	1.1	45	2.8	0.135	-	-
Abdominal w/o obstetric surgery	49	28.0	444	27.2	0.438	-	-
Gastrectomy	4	2.3	11	0.7	0.0491	3.451	0.295
BII-resection	5	2.9	31	1.9	0.265	-	-
Existence of blind loops	8	4.6	41	2.5	0.0942	1.861	0.549
Any resecting gastric surgery	12	6.9	45	2.8	0.0071	2.600	0.402
Resection of Ileocecum	7	4.0	41	2.5	0.176	-	-
Appendectomy	7	4.0	134	8.2	0.0271	0.466	2.050
Functional appendectomy	14	8.0	175	10.7	0.163	-	-
Cholecystectomy	8	4.6	127	7.8	0.0782	0.568	1.700
Resection of small intestine	11	6.3	80	4.9	0.260	-	-
Any colonic resection	19	10.9	97	5.9	0.0131	1.930	0.547
Sigmoid resection	3	1.7	13	0.8	0.196	-	-
Vagotomy	2	1.1	6	0.4	0.177	-	-
Fistula	2	1.1	16	1.0	0.532	-	-
Stenosis	10	5.7	29	1.8	0.0031	3.354	0.311
Impaired motility	17	9.7	9	0.6	< 0.0011	5.157	0.202
Gastroparesis	5	2.9	24	1.5	0.0301	3.403	0.300
Neuropathy	9	5.1	39	2.4	0.0371	2.217	0.464
Opioid use	10	5.7	55	3.4	0.0902	1.740	0.589

¹Statistical significant with P value P < 0.05;

²Statistical tendency with P value 0.05 < P < 0.1 χ² test each. Overall abdominal surgery was not associated with an increased risk of developing SIBO. Resecting gastric surgery in general and gastrectomy was associated with the development of SIBO. Patients with SIBO were less likely to have a history of appendectomy and - as a tendency - cholecystectomy. Ileocecal resection had no impact on the development of SIBO. As a further anatomical alteration, stenoses were more frequent in SIBO patients. Impaired motility, as shown by gastroparesis, led to SIBO; patients with neuropathy or opioid medication are patients at risk. SIBO: Small intestinal bacterial overgrowth.