Types of Stoma: Classification, Selection, and Differences

I. Classification by Content Drained

1. Fecal Stomas

a. Ileostomy

• Created from the ileum (small bowel)
• Output is liquid to semi-liquid, high-volume, and contains active digestive enzymes — corrosive to peristomal skin
• Requires a spouted/everted maturation (Brooke ileostomy) to protect skin from liquid effluent
• Located in the right iliac fossa
• More common as a temporary diverting stoma

b. Colostomy

• Created from the colon
• Output varies by location:
  • Ascending colostomy: liquid effluent (rarely used; poorly tolerated)
  • Transverse colostomy: semi-formed; prone to prolapse — generally avoided
  • Descending / Sigmoid colostomy: formed stool; preferred when permanent colostomy is needed
• Located in the left iliac fossa (for sigmoid/descending)
• Typically flush with skin (does not need to be spouted)

"Ascending colostomies tend to have a higher amount of liquid effluent, whereas descending and left-sided colostomies are usually preferable because most of the colon is in circuit, allowing for more colonic water absorption, with a more formed effluent." — Sabiston Textbook of Surgery, p. 2073

2. Urinary Stomas

• Ileal conduit (urostomy): segment of ileum used to divert urine; output is continuous and watery
• Described in urologic surgery for bladder removal (e.g., cystectomy)

II. Classification by Configuration

1. End Stoma

• The proximal cut end of bowel is brought through the abdominal wall; distal end is either removed or closed (Hartmann's pouch)
• Single lumen visible
• Used for permanent stomas (e.g., after APR for rectal cancer) or when distal bowel is resected
• Simpler appliance management; easier pouch adherence

Clinical photograph — End ileostomy:

2. Loop Stoma

• A loop of bowel is brought through the abdominal wall and opened; both lumens (proximal/afferent and distal/efferent) are visible on the surface, connected by an intact posterior wall
• A stoma rod/bridge is placed under the loop temporarily to prevent retraction
• Predominantly temporary — used for fecal diversion
• Easier to close than an end stoma
• Loop ileostomy is preferred for temporary diversion: odorless, easy to manage, easy to reverse
• Loop transverse colostomy should be avoided — large, prone to prolapse, difficult pouching (often at belt line)

Clinical photograph — Loop ileostomy with stoma rod:

3. Double-Barrel Stoma

• The bowel is completely divided; both ends are brought out as two separate stomas on the abdominal wall (proximal functioning limb + distal mucous fistula)
• Two discrete lumens — no intact posterior wall (distinguishes it from a loop stoma)
• Chosen in emergency cases, significant inflammation, complex procedures, or when there is concern about anastomotic integrity
• Provides complete fecal diversion

Clinical photograph — Double-barrel ileostomy:

4. End-Loop Stoma

• A hybrid: the loop is brought through the fascia and the mesenteric side is oversewn so that only the functioning end is opened
• Useful in obese patients where mobilizing enough colon for a true end stoma is technically difficult
• Provides the pouching advantages of an end stoma while requiring less bowel length

III. Classification by Permanence

IV. Classification by Continence

V. Stoma Site Selection

Stoma site marking — the stoma should ideally lie within the rectus muscle, visible to the patient, away from bony prominences, skin folds, and scars.

• Mark preoperatively (ideally with stomal therapy nurse)
• Within the rectus abdominis muscle (reduces parastomal hernia risk)
• Away from bony prominences, belt line, skin creases, previous scars, and umbilicus
• Visible to the patient (infraumbilical fat mound is ideal in most patients)
• Aperture should admit two fingers comfortably

VI. Stoma Selection During Surgery — Decision Guide

"Loop ileostomies are often chosen for temporary diversion because of their lack of odor, ease of care, and ease of closing. Transverse loop colostomies should seldom be used because they are large and are very prone to prolapse, and it can be difficult to maintain pouch adherence." — Sabiston Textbook of Surgery, p. 2072

VII. Key Differences at a Glance