Endoscopy: Definition, Types & Clinical Impact

Endoscopy is the visual examination of internal organs or cavities using a flexible or rigid endoscope—a lighted, camera-equipped instrument inserted through natural orifices or small incisions.

Major Types

Procedure	Target	Access Route
EGD / Upper Endoscopy	Esophagus, stomach, duodenum	Oral
Colonoscopy	Entire colon, terminal ileum	Anal
Sigmoidoscopy	Rectum, sigmoid colon	Anal
ERCP	Biliary/pancreatic ducts	Oral (duodenoscope)
Bronchoscopy	Trachea, bronchi	Oral/nasal
Cystoscopy	Bladder, urethra	Urethral
Hysteroscopy	Uterine cavity	Vaginal/cervical
Laparoscopy	Abdominal/pelvic cavity	Small incisions (ports)
Arthroscopy	Joint interior	Small incisions

Therapeutic Capabilities

• Biopsy, polypectomy, EMR/ESD, stricture dilation, stent placement.
• Hemostasis (clips, cautery, injection), foreign body removal.
• Stone extraction (ERCP), feeding tube placement (PEG).

Impact

• Replaced many exploratory surgeries; enables early cancer detection (colorectal, gastric, esophageal).
• Outpatient-friendly; lower morbidity, faster recovery, cost-effective.
• Screening colonoscopy reduces CRC incidence/mortality by >50%.

Endoscopy is a cornerstone of modern minimally invasive medicine.