Purpose:

1. Diagnose : Conditions like gastroesophageal reflux disease (GERD), stomach ulcers, duodenal ulcers, and esophageal cancer.

2. Monitor : Treatment progress or disease progression.

3. Treat : Certain conditions, such as removing polyps or performing dilation.

Procedure:

1. Preparation : Patient lies on their back, and a local anesthetic is sprayed to numb the throat.

2. Insertion : The endoscope is inserted through the mouth and guided through the esophagus, stomach, and duodenum.

3. Examination : The doctor visually examines the inner lining of the esophagus, stomach, and duodenum, taking biopsies or performing treatments as needed.

4. Removal : The endoscope is slowly withdrawn.

Risks and Complications:

1. Bleeding : From biopsies or polyp removal.

2. Perforation : Hole in the esophagus, stomach, or duodenum.

3. Infection : Rarely, bacteria can enter the bloodstream.

4. Reaction to sedation : Rarely, patients may experience adverse reactions.

Preparation and Aftercare:

1. Fasting : Patient must fast for 6-8 hours before the procedure.

2. Sedation : Patient may receive sedation to relax during the procedure.

3. Monitoring : Patient's vital signs are monitored during and after the procedure.

4. Recovery : Patient can usually go home after the procedure, but may experience some discomfort or bloating.