A range of diagnostic and therapeutic endoscopy is available. They are performed by surgeons and physicians, depending on the type. They include:

• Gastroscopy – study of the stomach and abdomen
• Colonoscopy – study of the large intestines
• Bronchoscopy – study of the airways of the lungs
• Endoscopic Retrograde Cholangiopancreaticography – study of the bile ducts
• Rhinoscopy – study of the nasal passages.

When abnormalities are found, biopsy can be taken to ascertain the nature of the lesions. Polyps in the gut can be removed, without the need for an operation. Stones in the bile ducts can be removed. It can help in the placement of feeding tubes in the stomach or breathing tube in the airways.