C4A and metabolic dysfunction-associated steatotic liver disease: While there are no relevant studies in literature investigating type 4 BAM epidemiology, an old questionnaire-based study reported that 20% of patients treated with metformin had accelerated bowel transit times [87] A recent study also suggests that non-alcoholic fatty liver disease (NAFLD) is associated with increased hepatic BAs production and diarrhea, resulting in elevated serum C4 in this patients [88].