CHOLELITHIASIS (Gallstones) 

1. Definition

Cholelithiasis = presence of stones in the gallbladder.

• May be asymptomatic
• May present as biliary colic
• May lead to complications:
  Acute cholecystitis, choledocholithiasis, cholangitis, pancreatitis

2. Epidemiology

• Prevalence: 10–20% adults in Western population
• Increasing in India
• Female > Male (2–3:1)
• Incidence rises with age

Classic mnemonic:
“4 F’s” – Female, Fat, Forty, Fertile

3. Types of Gallstones

A. Cholesterol Stones (Most common – 70–80%)

Features:

• Yellow
• Radiolucent on X-ray
• Formed due to cholesterol supersaturation

Pathogenesis 

1. ↑ Cholesterol secretion into bile
2. ↓ Bile salts / phospholipids
3. Gallbladder stasis
4. Nucleation → crystal aggregation

B. Pigment Stones

1. Black Pigment Stones

• Hard, brittle
• Associated with:
• Haemolysis
• Cirrhosis

2. Brown Pigment Stones

• Soft
• Associated with:
• Infection
• Biliary stasis
• Common in Asia
• Often in bile ducts

4. Risk Factors 

5. Clinical Presentation

A. Asymptomatic (Most common)

• Incidental finding on ultrasound
• No treatment required

B. Biliary Colic

Pain characteristics:

• Severe RUQ or epigastric pain
• Radiates to right shoulder/scapula
• Lasts 30 minutes – 6 hours
• Often after fatty meal
• No fever

Mechanism:
Transient cystic duct obstruction

C. Complications

6. Investigation

 First Line: Ultrasound Abdomen

Typical findings:

• Echogenic focus
• Posterior acoustic shadow
• Mobile with position change

Sensitivity > 95%

LFT Pattern

• Normal in simple biliary colic
• Cholestatic pattern if CBD obstruction:
• ↑ ALP
• ↑ GGT
• ↑ Bilirubin

When to do MRCP?

• Suspected choledocholithiasis
• Dilated CBD
• Abnormal LFTs

7. Management

A. Asymptomatic Gallstones

No treatment

Exceptions 

• Porcelain gallbladder
• Gallstones >3 cm
• Sickle cell disease
• Gallbladder polyps >1 cm
• Planned bariatric surgery

B. Biliary Colic

Acute Episode:

• NSAIDs (first-line: diclofenac IM)
• Opioids if needed
• Antiemetics

Definitive:

• Elective laparoscopic cholecystectomy

C. Acute Cholecystitis

• Admit
• IV antibiotics
• Early laparoscopic cholecystectomy (within 72 hours preferred)

D. Medical Dissolution Therapy

• Ursodeoxycholic acid
• Only for:
• Small cholesterol stones
• Functioning gallbladder
• Patient unfit for surgery
• High recurrence rate

E. ERCP Indications

• CBD stones
• Cholangitis
• Obstructive jaundice

8. Complications of Cholelithiasis

# Acute Cholecystitis(Persistent obstruction → inflammation)

# Gallstone Pancreatitis(Transient ampullary obstruction)

# Ascending Cholangitis

Charcot triad:

• Fever
• Jaundice
• RUQ pain

Reynolds pentad:

• Hypotension
• Confusion

9. Clinical Differentials

10. Gallstone Ileus

Rigler triad:

• Pneumobilia
• Small bowel obstruction
• Ectopic gallstone

11. Mirizzi Syndrome

Stone in cystic duct compresses common hepatic duct → obstructive jaundice.