**4.4 Anterior resection syndrome**

Following TME, postoperative defecation dysfunctions known as "anterior resection syndrome" might appear.

Straight colorectal anastomosis (SCA), colon J-pouch (CJP), and side-to-end anastomosis are all common reconstruction techniques (SEA) (**Figures 14** and **15**).

There are no prospective, randomized, multi-center trials that compare their functional results, including long-term evaluations.

As a result, the primary endpoint of a study designed by Marti and collab [14] that included 336 patients from 15 hospitals who were randomized had a comparison of composite evacuation scores 12 months after TME as a primary endpoint.

Secondary endpoints included a comparison of composite evacuation and incontinence ratings at 6, 18, and 24 months after surgery, as well as morbidity and overall survival.

The study looked at the "per protocol" (PP) population, which complied with all-trial criteria, as well as the "intention-to-treat" (ITT) population.

At any time point, there were no statistically significant variations in the composite evacuation ratings of the PP and ITT populations.

Similarly, at any time point, there was no statistically significant difference in composite incontinence scores for the PP and ITT populations among the three trial weapons.

Conclusions: Within the scope of the investigation, surgeons in charge can continue to conduct intestinal continuity reconstruction following TME at their discretion.

In addition to the studies previously reported, Hou and collab [15] investigated whether the use of side-to-end anastomosis (SEA) in sphincter-preserving resection (SPR) is problematic and conducted a meta-analysis to compare the safety and efficacy of SEA with colonic J-pouch (CJP) anastomosis, which has been shown to improve postoperative bowel function.

The meta-analysis included a total of 864 patients from 10 RCTs.

At 12 months after SPR, patients who underwent SEA had a higher defecation frequency and a lower incidence of incomplete defecation than those who underwent CJP anastomosis with low heterogeneity and a lower incidence of incomplete defecation at 3 months after surgery.

*The Problem of the Colorectal Anastomosis DOI: http://dx.doi.org/10.5772/intechopen.100302*

**Figure 14.** *Types of anastomoses illustrated.*

**Figure 15.** *Aspect of the J-pouch.*

The SEA group also had a shorter operating period with no substantial heterogeneity.

The SEA group had a higher anorectal resting strain, but there was a lot of heterogeneity.

There were no significant differences between the groups in terms of efficacy outcomes such as defecation frequency, urgency, incomplete defecation, use of pads, enema, medications, anorectal squeeze pressure, and maximum rectal volume, or safety outcomes such as operating time, blood loss, use of protective stoma, postoperative complications, clinical outcomes, and complication rates.

In comparison with CJP anastomosis, the current evidence indicates that SEA is a successful anastomotic technique for achieving comparable postoperative bowel function without raising the risk of complications.

Shorter operating times, a lower occurrence of incomplete defecation three months after surgery, and improved sphincter function are all advantages of SEA.

However, after SPR, long-term defecation frequency should be closely monitored.
