1 Double Contrast Enema: Technical Aspects.- 1.1 Preparation of the Patient.- 1.2 Barium Preparation.- 1.3 Material.- 1.4 Radiologic Examination.- 1.5 Contraindications.- 1.6 Complications.- 1.7 Conclusion.- References.- 2 Interpretation (General Rules, Normal and False Images).- 2.1 General Rules of Interpretation.- 2.2 Colonic Morphology and Motor Activity.- 2.3 Normal Appearance of the Colonic Mucosa (Walls and Margins), Physiologic Variants, False Images.- 2.4 Interpreting the Examination.- References.- 3 Radiologic Signs in Tumoral Pathology: Polyps and Polyposis Syndromes.- 3.1 Introduction.- 3.2 Polyps.- 3.3 Colonic Polyposis.- References.- 4 Primary Colorectal Cancer.- 4.1 Nonspecific Radiologic Appearances of Colorectal Carcinoma.- 4.2 Radiologic Signs Indicating the Malignant Nature of a Polyp.- 4.3 Classic Appearances of Primary Colorectal Carcinoma.- 4.4 Effectiveness of the Double Contrast Enema in Colorectal Carcinoma.- References.- 5 Villomas.- 5.1 Nonspecific Features.- 5.2 Indicative and Specific Features.- 5.3 The Radiologic Diagnosis of Malignancy Remains Problematic.- References.- 6 Ulcerative Colitis.- 6.1 Radiologic Pathology.- 6.2 Radiologic Appearance.- 6.3 Differential Diagnosis.- References.- 7 Crohn's Disease of the Colon.- 7.1 Pathology.- 7.2 Correspondence of Radiologic Images to the Lesions.- 7.3 Conclusion.- References.- 8 Colonic Diverticulosis.- 8.1 Physiopathogenic Review.- 8.2 Pathology Review.- 8.3 Radiologic Aspects of Colonic Diverticulosis.- 8.4 Diverticulosis and Diverticulitis.- 8.5 Diverticulosis and Associated Lesions.- 8.6 Conclusion.- References.- 9 Conclusion.