Study of the Effect of Water Soluble Oral Contrast (Gastrografin) on Postoperative Ileus After Colorectal Surgery

Inclusion Criteria: * All patients with postoperative ileus after colorectal surgery, defined as the presence from the third postoperative day, abdominal distension, nausea, vomiting with or without abdominal pain or discomfort by dilation of bowel loops, confirmed radiology of the abdomen, and which are: Age \> 18 years Patients undergoing laparotomy or laparoscopy for the following variants of colorectal disease with or without stoma: 1. Neoplasia. 2. Inflammatory disease. 3. Diverticular disease. Patients who have been treated with standard PCA as postoperative analgesia. Signed informed consent. Undergoing elective or scheduled Exclusion Criteria: * Patient's refusal to sign informed consent * Pregnancy or lactation * Hypersensitivity to iodinated contrast agents (it´s the only contraindication to oral Gastrografin) Presence of other problems that justify the etiology of postoperative ileus: 1. Anastomotic leakages. 2. Mesenteric vascular disease. 3. Incarcerated hernias. 4. Intra-abdominal abscesses or collections. 5. Metabolic or electrolyte disturbances. If during the course of the study one of the reasons previously cited as the etiology of postoperative ileus is present, the patient shall also be excluded. Also excluded patients undergoing emergency surgery.