If the injury is to the bowel itself, at this point in the operation you should be looking at several rapidly closed holes with long silk tags, or areas of hematoma adjacent to the colon or at the bowel/mesentery junction without frank spill. The first step is to avoid the temptation to start contending with the holes that you know you have and instead fully define all of the injuries with which you are dealing. This may save you from wasting time on primary repairs that will later wind up in a resected piece of bowel after other injuries are discovered. While this is frequently straightforward, a few particulars are worth mentioning. First, any pericolonic hematoma needs to be completely inspected. This means rolling the colon and dissecting all other tissues away until only the colonic serosa remains. If a subserosal hematoma is found, unroof it. Similarly, any hematoma at the junction of the bowel wall and mesentery should be considered to be an injury until proven otherwise by direct visual inspection of the serosa of the involved area. Do not let the fear of an iatrogenic injury stop you from completely inspecting the area of concern. Occasionally, for injuries close to the root of the mesentery, it will be necessary to actually take the ligament down. The important thing to remember is to never look at a hematoma immediately adjacent to a viscus and leave it thinking that it is probably OK. In the words of the esteemed surgeon Benton DuPont, “That works about as well as ball bearing book ends.” Similarly, an odd number of holes in the bowel should trigger fears for a missed injury. While tangential wounds can occur, the finding of an odd number of holes should cause one to spend extra time looking for a missed perforation. Keep in mind the mobility of the small bowel, that people get shot in all manner of bodily positions, and that bullets do not travel in straight lines. In short, when looking for bowel injuries, paranoia is a healthy attitude.

Once an injury to the bowel wall is located, debriding the edges to healthy tissue and a transversely oriented primary repair should be the default first choice. Personally, we prefer a single-layer running suture. If we have a relatively short segment of the small bowel that has been fluted, we will resect it in order to minimize the number of suture lines. When making the decision about whether or not to resect an intervening piece of small bowel between two injured segments in order to save an anastomosis, we will check to see if we are leaving the patient with at least 250 cm of small bowel if a resection is performed as short bowel syndrome should not be a concern with that length. In adults, particularly those lacking a functional colon, lifelong TPN dependence is likely to occur in those who have 100 cm or less. While the presence of a functional ileocecal valve is thought to increase this length to an unknown degree, trauma patients are clearly at higher risk for subsequent bowel resections at their initial admission as well as over their lifetime (trauma recidivism rates are significant, proving the old saying, “Trauma is a chronic disease with acute exacerbations”). Given that, it is smart to leave them with plenty of bowel to spare. When dealing with two enterotomies that are within a centimeter or so of each other, the bridging wall of bowel separating them can become devascularized and slowly necrose over the course of a few days. Avoid the temptation to perform two primary repairs in this setting, as it is prudent to debride this segment and convert them into one larger enterotomy which can then be closed easily.

If a resection is required, the decision to perform an anastomosis versus diversion has vexed generations of surgeons. During World War II, failure to treat a penetrating colon injury with diversion was a court martial offense. With time, as it came to be realized that civilian injuries are not necessarily equivalent to military injuries and that ostomy reversal carried its own morbidity, the pendulum began to swing toward a lower threshold for anastomosis at the time of the first operation. In the stable, previously healthy penetrating trauma patient who is exhibiting no signs of shock and has received no blood products, we will always perform a primary anastomosis regardless of the location of the injury or the amount of peritoneal soilage from stool. This includes left colon injuries. The one exception to this general rule is the elderly patient with minimal physiologic reserve. In that setting, we will still perform enteroenterostomy and enterocolostomy. When considering the higher risks of colocolostomy in conjunction with the fact that an anastomotic leak in this specific population is often a death sentence, we will generally opt to perform resection and diversion in those patients. One should realize though that frequently means these will become permanent ostomies.

Typically the stable patient has relatively normal caliber bowel, and if this is the case, either hand-sewing or stapling the anastomosis should be fine.