Table 2.

Causes of secondary hyperoxaluria

Categories	Examples
Increased oxalate precursors	Ingesting high quantities of ethylene glycol, peanuts, rhubarb, vitamin C, cashew pseudofruit
Fat malabsorption	Small bowel resection, bariatric surgery, chronic pancreatitis, systemic sclerosis, cystic fibrosis, Crohn’s disease, Celiac disease
Intestinal decolonization of oxalate-degrading bacteria species such as Oxalobacter formigenes	Antibiotic use, small intestine bacterial overgrowth, Clostridium difficile infection
Increased colonic permeability to oxalate	Inflammatory bowel disease, C. difficile infection
Drugs	Orlistat, octreotide, mycophenolate mofetil, hydroxocobalamin