Conditions where bile flow is impaired, leading to accumulation of bile acids in the liver and blood.

Examples:

• Primary Biliary Cholangitis (PBC)
• Primary Sclerosing Cholangitis (PSC)
• Biliary Atresia (in infants)
• Drug-induced cholestasis

Consequences:

• Hepatocellular injury (bile acids are cytotoxic in excess)
• Fat malabsorption
• Pruritus (itching due to bile acid buildup)

Caused by supersaturation of bile with cholesterol due to:

• Imbalanced bile acid–cholesterol ratio
• Decreased bile salt secretion

Risk factors:

• Female, Fat, Forty, Fertile, Family history
• High estrogen levels
• Obesity

Occurs when excess bile acids reach the colon, stimulating secretion and motility.

Types:

• Primary BAD – idiopathic
• Secondary BAD – after ileal resection, Crohn’s disease, radiation enteritis

Symptoms:

• Chronic watery diarrhea, urgency

Bile acids are essential for absorption of vitamins A, D, E, and K.

Causes:

• Cholestasis
• Liver dysfunction
• Bile duct obstruction

Symptoms:

• Night blindness (vit A), bleeding (vit K), bone weakness (vit D), neuropathy (vit E)

Genetic Diseases:

• Progressive Familial Intrahepatic Cholestasis (PFIC)
• Bile acid synthesis disorders (e.g., CYP7A1, CYP27A1 mutations)

Altered bile acid signaling through FXR and TGR5 receptors is linked to:

• Type 2 Diabetes
• Non-Alcoholic Fatty Liver Disease (NAFLD)
• Obesity
• Dyslipidemia