Digestive Endoscopy: Types, Indications and Procedures of Endoscopic Examinations of the Digestive System

The two main endoscopic examinations of the digestive system are esophagogastroduodenoscopy or gastroscopy and colonoscopy.

These diagnostic techniques provide images that make it possible to visually identify any pathology of the entire digestive tract, from the esophagus to the colon.


Gastroscopy, or esophageal-gastric-duodenoscopy, is a medical procedure that examines the first part of the digestive system or upper digestive tract (esophagus, stomach, and duodenum).

Through a thin, flexible probe (endoscope) that has an attached video camera that transmits images to a monitor.

Gastroscopy allows the evaluation of all possible diseases present in these upper tracts.

Diseases found through images transmitted from the endoscope can be confirmed by histological examination carried out on samples taken during the same endoscopic examination.


Colonoscopy allows the evaluation of the entire colon and the distal segment of the ileum, diagnosing all chronic inflammatory bowel diseases that can affect this part of the intestine and polyps and tumors.


With colonoscopy, it is possible to diagnose the presence of intestinal polyps that, if left untreated, can turn into tumors in about ten years.

Therefore, the importance of this procedure for the prevention of cancer is evident.

The national bowel disease screening program, due to financial constraints, includes only patients ages 50 to 60 who have occult blood in their stools.

But in recent years, it has been discovered that colon cancer also affects patients under the age of 50.

For this reason, all cases with blood in the stool should be evaluated using a colonoscopy, even if it is not provided by the national examination due to age reasons.

Colonoscopy is also helpful in diagnosing chronic inflammatory bowel diseases in people ages 20 to 50.

Situations that require a digestive endoscopy

Among the diseases that usually require a digestive endoscopy are:

Your doctor will recommend an endoscopy when the following symptoms occur:

  • Epigastric pain.
  • Swelling after meals.
  • Acidic or alkaline regurgitation (burning, bitter taste in the mouth).
  • Dyspepsia .
  • Significant weight loss for a limited period (5 to 6 kg in two months).
  • Hypersalivation

A colonoscopy is necessary if the following symptoms are observed:

  • Patients who experience a change in the frequency and consistency of bowel movements (e.g., constipation, diarrhea with alternating constipation).
  • In cases of bleeding.
  • Patients with irritable bowel syndrome and abdominal pain.
  • For patients undergoing colon cancer prevention screening, tests positive for fecal occult blood.
  • Significant weight loss for a limited period (5 to 6 kg in two months).

Therapeutic endoscopies

Endoscopic studies not only aid in diagnosis; They help treat certain conditions, such as:

  • Hemorrhagic ulcers.
  • Bleeding esophageal varicose veins (varicose vein tie).
  • Resection of polyps (endoscopic polypectomy).
  • Esophageal stricture dilation.
  • Placement of feeding catheters (endoscopic gastrostomy).
  • Endoscopic retrograde cholangiography.



The exam does not require any specific preparation, in addition to a 6-hour fast.

Gastroscopy can be performed under light or deep sedation; the latter is recommended because it offers more comfort for the patient.

The procedure is carried out by introducing the instrument (gastroscope), equipped with a video camera that sends images to a monitor.

The procedure takes about 3 minutes, and after a couple of hours, the patient can eat regularly.

It is an evaluation that does not carry particular risks for the patient (side effects are almost non-existent).

Sedation can be achieved using a local anesthetic, applied to the back of the tongue and soft palate to reduce the sensation of nausea.

If gastroscopy reveals the presence of gastric polyps, biopsies may be performed (that is, small tissue samples are taken and sent to the laboratory for analysis).

It can be accomplished during the endoscopic procedure if gastric polyps need to be removed.


This procedure is done using a thin, flexible tube (colonoscope) inserted through the anus.

This probe has a video camera that transmits images to a monitor. The colon must be completely clean for this exam.

A diet must be followed in this procedure, and medications are taken to cleanse the intestine the day before the evaluation.

This preparatory phase is crucial for the diagnostic validity and safety of the procedure.

The diet should be started 4 to 5 days before the procedure.

Colonoscopy is usually done with deep sedation.

The procedure lasts 15 to 20 minutes and involves the introduction of the instrument from the anus through the entire length of the colon to the cecum.