The purpose of this study is to asses the safety and efficacy of early stoma closure (2-3 weeks after total mesorectal excision) vs late closure (16-24 weeks after mesorectal excision).

Total mesorectal excision (TME) is considered the gold standard in obtaining a negative circumferential resection margin for cancers of the middle and lower third of the rectum. Despite all the oncological benefits,TME in ultra-low anterior resection carries some important drawbacks, such as a longer operative time, and its association with a higher rate of anastomotic leakage which increases in the most distal anastomoses.

Among the measures adopted to reduce mortality, the creation of protective ostomies has proven to be effective, however the protective ileostomy and its closure are not free of complications, such as dehydration and chronic kidney failure. In the investigator's country, various studies have analyzed this time to closure, being 10.8 months on average and with an increase in morbidity when closure is delayed the longest.

There are few prospective studies on the timing of stoma closure, which mainly focused on morbidity and mortality related to early closure. These studies did not demonstrate any significant negative effects on morbidity or mortality. The reason for early closure of the stoma is to reduce complications related to it. Although its true incidence is unknown, most patients have some type of stoma-related complication, which can be avoided or decreased in the case of early closure. In addition to the complications on the patient and their quality of life, the hospital costs secondary to them are not negligible.

The TIMES study ("TIMing Evaluation of Stoma closure") arises from the need to know the ideal moment for the closure of derivative stomata after rectal surgery.

Therefore, the hypothesis is that patients who undergo early ileostomy closure (at 2-3 weeks) after ultra-low anterior resection have fewer complications than patients with late ileostomy closure (4-6 months).

The main objective of this study is to analyze the morbidity and mortality associated with both early (early group, CASES group) and late closure (late group, CONTROL group) of the derivative ileosomy.

In this study, patients scheduled for temporary stoma closure after scheduled colorectal surgery will be randomized into two groups: early closure (14-21 days after surgery) or late closure (4th-6th month after surgery).

Patients will be followed from the time of study entry until 12 months after stoma closure.

Inclusion Criteria:

• Patients with rectal cancer (with / without metastasis) (with / without chemoterapy or radiotherapy)
• Patients undergoing low or ultra low anterior resection with anastomosis and stoma of protection.
• Patients with no intraoperative or postoperative complications.
• Radiological confirmation of the absence of anastomotic compilations (opaque enema or abdominal-pelvic CT scan with rectal contrast)
• Confirmation by rectoscopy of the absence of anastomotic compilations

Exclusion Criteria:

• Rectal cancer surgeries without anastomosis.
• Rectal cancer surgeries without stoma of protection.