Aetiology and associated risk factors for development of SIBO
| Gut dysmotility | Altered GI secretions | Anatomical alterations | Impaired immunity |
| Diabetes mellitus | Medications—proton pump inhibitors | Roux-en-Y gastric bypass | Hypogammaglobulinaemia |
| Connective tissue disorders for example, systemic sclerosis, Ehlers Danlos | Chronic pancreatitis | Strictures, adhesions, fistulae (Crohn’s) | Combined variable immunodeficiency |
| Visceral neuropathies and myopathies | Chronic liver disease | Ileocecal valve impairment /resection Gastrectomy | |
| Medications—opioids, anticholinergics | Small bowel diverticular disease | ||
| Parkinson’s disease Radiation enteropathy |
GI, gastrointestinal; SIBO, small intestinal bacterial overgrowth.