Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 15-27: Malabsorption + Key Features Download Section PDF Listen +++ ++ Overgrowth of bacteria in normally sterile segments of small bowel; may result in malabsorption of fat with steatorrhea Causes include Gastric achlorhydria Anatomic abnormalities of the small intestine with stagnation (afferent limb of Billroth II gastrojejunostomy, resection of ileocecal valve, small intestine diverticula, obstruction, blind loop) Small intestine motility disorders (vagotomy, scleroderma, diabetic enteropathy, chronic intestinal pseudo-obstruction) Gastrocolic or coloenteric fistula (Crohn disease, malignancy, surgical resection) Miscellaneous disorders + Clinical Findings Download Section PDF Listen +++ ++ Many patients are asymptomatic Flatulence, weight loss, abdominal pain, diarrhea, and sometimes steatorrhea May also be present in a subset of patients with irritable bowel syndrome Advanced cases associated with deficiencies of iron or vitamins A, D, and B12 + Diagnosis Download Section PDF Listen +++ ++ Stool fecal fat: corroborates presence of steatorrhea Small bowel CT or MR enterography or barium radiography: identifies mechanical factors predisposing to intestinal stasis Small intestinal biopsy Excludes other mucosal malabsorptive conditions (eg, celiac disease) Detects intestinal inflammation Aspirate and culture of proximal jejunal secretion > 105 organisms/mL establishes the diagnosis However, this test is not widely available Noninvasive breath tests are reported to have a sensitivity of 60–90% and specificity of 85% compared with jejunal cultures + Treatment Download Section PDF Listen +++ ++ Correct the anatomic defect when possible Ciprofloxacin, 500 mg twice daily orally, norfloxacin, 400 mg twice daily orally, amoxicillin clavulanate, 875 mg twice daily orally, or combination of metronidazole, 250 mg three times daily orally, and trimethoprim-sulfamethoxazole 160/800 mg twice daily orally, or cephalexin, 250 mg four times daily orally, for 1–2 weeks Rifaximin, 400 mg three times daily orally, is a nonabsorbable antibiotic that is effective and appears to have fewer side effects than systemic antibiotics If symptoms recur off antibiotics, cyclic therapy (eg, 1 week of every 4) may be sufficient Avoid continuous antibiotics to prevent bacterial antibiotic resistance Octreotide in small doses may be of benefit