COLON

Treatment of colon injuries is dependent upon the location:

Selecting the type of colostomy

::	Normally, a loop colostomy is the easiest
::	If you have to resect a piece of colon, perform a double-barrelled colostomy with the two free ends
::	Use an end colostomy when the distal stump is too short to exteriorize after the gangrenous or injured loop has been resected. This is particularly useful in the sigmoid colon and proximal rectum (Figure 6.48)
Figure 6.48
::	Use an end ileostomy after right colon resection when anastomosis is not performed.

Techniques

Determine the site for the colostomy at surgery. Make an incision separate from the main wound in the quadrant of the abdomen nearest to the loop to be exteriorized. Use the greater omentum as a guide to locate the transverse colon.

Loop colostomy

::	Bring out the loop of colon without kinking or twisting it (Figure 6.49). Make an opening in the mesocolon just large enough to admit a piece of glass rod. Push the rod halfway through the opening and attach its ends to the ends of a piece of polythene tubing (Figure 6.50, 6.51). As an alternative, insert a catheter through the mesocolon and join the ends with sutures of 2/0 thread. Close the wound around the exteriorized loop of gut.
Figure 6.49
Figure 6.50
Figure 6.51
::	The opening in the colon may be made immediately, provided that extreme care is taken to prevent mechanical contamination of the wound. Alternatively defer making the opening for 8 to 24 hours when there is less risk of wound contamination. Make a cruciate incision in the apex of the loop with a knife or diathermy (Figure 6.52). Pack petroleum gauze and gauze swabs around the colostomy.
Figure 6.52

Double-barrelled colostomy

::	Resect the gangrenous loop of colon as described for resection of the small intestine (see page 6–10). Mobilize the remaining colon so that the limbs to be used for the colostomy lie without tension.
::	Bring the two clamped ends of bowel out through a stab wound or gridiron incision and keep them clamped until the laparotomy incision has been closed (Figure 6.53). Then remove the clamps and fix the full thickness of the gut edge to the margin of the stab wound. Approximate mucosa to skin edge with interrupted 2/0 absorbable suture (Figures 6.54, 6.55). If a bag is not available, cover the colostomy with generous padding.
Figure 6.53
Figure 6.54
Figure 6.55

End colostomy

::	Bring out the proximal end of the colon through a gridiron incision (Figure 6.56). Close the distal stump of colon without further attempt at mobilization using two layers of stitches: an inner, continuous stitch of 2/0 absorbable suture covered by an outer seromuscular layer of interrupted 2/0 polyglycolic or non-absorbable suture (Figures 6.57 to 6.60). Attach a 5–6 long non-absorbable suture to the distal stump so that it can be found more easily at the time of re-anastomosis.
Figure 6.56
Figure 6.57
Figure 6.58
Figure 6.59
Figure 6.60
::	Drop this end of bowel back into the pelvis. Finally, stitch the proximal end to the margin of the stab wound.

Colostomy bags greatly ease the long-term care of the stoma.