Diagnostic and Therapeutic Digestive Endoscopy

What Is Diagnostic and Therapeutic Endoscopy

Endoscopy is a medical procedure that uses a flexible tube equipped with a camera and light source — called an endoscope — to examine the interior of the gastrointestinal tract. Modern endoscopes transmit high-definition video, allowing the physician to visualize the mucosa in extraordinary detail. Diagnostic endoscopy identifies conditions such as ulcers, inflammation, polyps, and tumors, while therapeutic endoscopy uses specialized instruments passed through the endoscope to treat those conditions during the same session. This dual capability makes endoscopy one of the most versatile tools in gastroenterology.

Upper Endoscopy (Gastroscopy)

What It Is

Upper endoscopy, also known as esophagogastroduodenoscopy (EGD) or gastroscopy, examines the esophagus, stomach, and duodenum. The endoscope is introduced through the mouth and gently advanced through the upper digestive tract. The procedure typically lasts 5 to 15 minutes.

Indications

• Persistent heartburn, acid reflux, or suspected gastroesophageal reflux disease (GERD) not responding to medication
• Difficulty swallowing (dysphagia) or painful swallowing
• Unexplained upper abdominal pain, nausea, or vomiting
• Investigation of anemia or suspected upper gastrointestinal bleeding
• Screening and surveillance for Barrett's esophagus or esophageal cancer
• Evaluation and biopsy of gastric ulcers or suspicious mucosal lesions
• Celiac disease confirmation through duodenal biopsies
• Surveillance of gastric polyps

Lower Endoscopy (Colonoscopy)

What It Is

Colonoscopy examines the entire large intestine (colon) and the terminal ileum. A longer, flexible endoscope is introduced through the rectum and advanced to the cecum. The procedure typically lasts 20 to 45 minutes, depending on findings and interventions.

Indications

• Colorectal cancer screening — recommended starting at age 45 (or earlier with a family history)
• Surveillance after prior polyp removal to check for recurrence
• Investigation of rectal bleeding, blood in stool, or positive fecal occult blood test
• Chronic diarrhea, unexplained change in bowel habits, or suspected inflammatory bowel disease (Crohn's disease, ulcerative colitis)
• Iron deficiency anemia of unknown origin
• Evaluation of abnormalities seen on imaging (CT, barium enema)

Therapeutic Capabilities

Modern endoscopy goes far beyond visualization. A wide array of therapeutic procedures can be performed during the same session:

• Polypectomy: Removal of polyps using snare electrocautery, cold snare, or endoscopic mucosal resection (EMR). This is a cornerstone of colorectal cancer prevention, as most colorectal cancers arise from adenomatous polyps.
• Hemostasis: Control of gastrointestinal bleeding using techniques such as injection therapy (adrenaline), thermal coagulation (heater probe, argon plasma coagulation), or mechanical methods (endoscopic clips). Endoscopy is the first-line treatment for acute upper and lower GI bleeding.
• Variceal banding: Endoscopic band ligation is the standard treatment for esophageal varices — dilated veins in the esophagus that develop in patients with liver cirrhosis and portal hypertension. Rubber bands are placed around the varices to prevent or treat variceal bleeding.
• Dilation: Strictures (narrowing) of the esophagus, pylorus, or colon can be widened using through-the-scope balloons or Savary-Gilliard dilators. This restores passage of food and alleviates dysphagia.
• Foreign body removal: Accidentally swallowed objects (coins, bones, batteries, dentures) can be safely extracted using endoscopic forceps, snares, or retrieval nets without surgery.

Colonoscopy Preparation

A thorough bowel preparation is essential for a successful colonoscopy. Inadequate preparation can obscure polyps and may necessitate a repeat procedure.

• Diet 3 days before: Begin a low-residue diet — avoid raw vegetables, whole grains, seeds, nuts, and high-fiber foods. Choose white bread, rice, pasta, lean meats, and cooked vegetables.
• Day before the procedure: Switch to clear liquids only — water, clear broth, apple juice, tea (no milk), and gelatin (not red or purple). Avoid solid foods entirely.
• Bowel preparation solution: Your doctor will prescribe a specific preparation (typically a polyethylene glycol solution such as Fortrans or a lower-volume option). Follow the split-dose regimen: take the first half the evening before and the second half early on the morning of the procedure. This split-dose approach produces the best colon cleanliness.
• Timing: Finish drinking the preparation at least 3 hours before your scheduled procedure time. Continue drinking clear fluids up to 2 hours before.
• Tips for drinking the prep: Chill the solution, use a straw, suck on lemon slices between glasses, and drink at a steady pace rather than gulping.

Step by Step

Gastroscopy

1. An IV line is placed and sedation is administered (typically propofol or midazolam with fentanyl).
2. A mouth guard is placed between your teeth to protect them and the endoscope.
3. The endoscope is gently inserted through the mouth and advanced through the esophagus, stomach, and into the duodenum.
4. Air or CO2 is insufflated to gently distend the walls and allow detailed visualization.
5. The mucosa is carefully inspected. Biopsies are taken from any suspicious areas using tiny forceps passed through the endoscope.
6. Therapeutic interventions are performed as needed (polyp removal, hemostasis, dilation).
7. The endoscope is withdrawn, and you are transferred to the recovery area.

Colonoscopy

1. After sedation, you are positioned on your left side.
2. The colonoscope is introduced through the rectum and carefully advanced through the sigmoid colon, descending colon, transverse colon, ascending colon, and cecum. In many cases, the terminal ileum is also intubated.
3. During withdrawal, the endoscopist performs a thorough inspection of the colonic mucosa. The withdrawal time should be at least 6 minutes to ensure adequate examination.
4. Polyps are identified and removed in real time. Biopsies are taken from any abnormal-appearing tissue.
5. The endoscope is withdrawn, and you are taken to recovery.

Possible Risks

• Bleeding: May occur at the site of a biopsy or polypectomy. Most bleeding is minor and self-limited. Post-polypectomy bleeding occurs in approximately 1% of cases and can usually be managed endoscopically.
• Perforation: A rare complication (approximately 0.1% for colonoscopy, less for gastroscopy). If perforation occurs, surgical repair may be necessary, though endoscopic closure with clips is increasingly feasible.
• Sedation-related events: Temporary drops in oxygen levels or blood pressure may occur. Continuous monitoring by the anesthesia team ensures these are promptly addressed.
• Post-polypectomy syndrome: Localized abdominal pain and mild fever after large polyp removal, caused by a thermal injury to the bowel wall without perforation. It is managed conservatively with antibiotics and rest.

After the Procedure

• Recovery: You will be monitored for 30 to 60 minutes. Once you are fully awake and comfortable, you may be discharged.
• Diet: You can eat and drink normally after the procedure unless your doctor specifies otherwise. After a colonoscopy, start with light meals and increase as tolerated.
• Bloating: Abdominal bloating and gas are common after colonoscopy due to air insufflation. Walking gently helps relieve this.
• Biopsy results: If biopsies were taken, results are typically available within 5 to 7 working days.
• Polyp follow-up: If polyps were removed, your doctor will recommend a surveillance schedule based on the number, size, and pathology of the polyps — typically a repeat colonoscopy in 1, 3, or 5 years.
• Warning signs: Contact your doctor if you experience severe abdominal pain, persistent rectal bleeding, fever, or chills.

Practical Tips

• For colonoscopy prep, stay close to a bathroom and consider applying a barrier cream to prevent skin irritation.
• Wear comfortable, loose-fitting clothes on the day of the procedure.
• Do not make important decisions, drive, or operate machinery for 24 hours after sedation.
• Bring a list of your current medications and any relevant medical records to your appointment.
• Do not be embarrassed — endoscopy teams perform these procedures daily and prioritize your comfort and dignity throughout the process.
• If you have questions or anxiety about the procedure, discuss them with your doctor in advance. Understanding the process reduces stress significantly.