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Diagnostic Methods

Author/s: Dr. Javier Nebreda, Dra. Dolores Maluenda Colomer

Flexible sigmoidoscopy

This technique consists in introducing a thin tube with a light through the rectum for about 60 cm to look for polyps, anormal areas and cancer. This technique allows the clinician to diagnose over half of all colon cancers and to take biopsy samples of tissue, if necessary.
It is a radiological technique that allows to see the silhouette of the colon after the introduction of a barium contrast through the rectum.

Barium enema is a reasonable, though less effective, alternative, useful if colonoscopy – conventional or virtual – is not available or if the patient does not have to undergo sedation. However, if a polyp is detected, it cannot be removed immediately during the test, as is the case during colonoscopy.

Opaque enema

An opaque enema is a radiological technique that enables visualisation of the shape of the colon after introducing a barium contrast through the rectum.

A barium enema is a less effective but useful reasonable alternative if colonoscopy is not available –conventional or virtual- or if the patient cannot be sedated.

Nevertheless, if a polyp is detected, it would not be possible to excise it right away as done in a colonoscopy.

Rectal palpation

A rectal digital examination consists in the examination of the rectum. The doctor introduces a finger protected by a lubricated glove through the rectum in search of masses or abnormal areas.