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Enlarging the Opening of an Ostomy Pouch System: When and How. A Report of 5 Cases

Special Report

Enlarging the Opening of an Ostomy Pouch System: When and How. A Report of 5 Cases


Ostomy literature and product instructions vary on recommendations for the size of the ostomy pouch opening, but none recommend an opening larger than 1/8 inch (3.175 mm) unless recommended by a wound, ostomy, continence (WOC) nurse or health care professional. The purpose of this case report is 2-fold. First, it identifies when the clinician might consider enlarging the pouch opening beyond the typically recommended 1/8-inch maximum. Second, it identifies how the clinician can protect the exposed peristomal skin. The report was prepared by certified WOC nurses (CWOCNs) with almost 100 years combined experience in ostomy care and describes 5 complicated patients in which pouch openings larger than 1/8 inch beyond the stoma edge were created to improve pouch wear time, decrease supply usage and cost, and improve patient satisfaction.

The authors, all WOC nurses, have identified circumstances when a larger opening may be helpful. Case studies are used to describe these circumstances and how to enlarge the pouch opening.  


Ostomy pouches collect stool or urine following a surgical diversion. These devices are available in 1- and 2-piece options. One-piece systems include a pouch with an attached adhesive-backed skin barrier that is secured on the skin; 2-piece systems include a pouch and an unattached adhesive-backed skin barrier that are joinable before or after securing on the skin. For simplicity, the term pouch will be used to describe both options.

A key aim of pouching is to protect peristomal skin.1 Skin can be protected with a pouch opening no larger than 1/8 inch greater than the stoma. However, other products can be used to protect peristomal skin including moisture insoluble skin barrier sprays or wipes, skin barrier rings, skin cement, skin barrier powder, skin barrier strips, and skin barrier paste.

WOC nurses help patients determine the size and shape of the pouch opening that best fits their individual stoma. Although recommendations in the ostomy literature (including textbooks, guidelines, and product instructions) are very similar, recommendations regarding the size of the pouch opening can differ. Some instructions suggest cutting the pouch to the size and shape of the stoma or skin/stoma (mucocutaneous) junction,1-4 others advise cutting the opening larger than the stoma with minimal skin exposed,5,6 some guidelines propose leaving no more than a 1/8 inch gap between the edge of the pouch opening and the stoma,7-11 and some sources do not make any recommendations as to the correct size of the pouch opening. In addition to the 1/8-inch recommendation, the Wound, Ostomy, and Continence Nurses Society adds “unless otherwise instructed by your WOC nurse or health care provider.”7 Situations conducive to a larger opening include ileostomy obstruction12 and stomal prolapse.13

When considering an opening >1/8 inch beyond the stoma edge, the type of ostomy and effluent must be taken into account. Descending or sigmoid colostomies often pass formed stool that is less irritating to the skin (unlike ileostomies that produce frequent, and sometimes continuous, liquid or mushy stool containing digestive enzymes harmful to skin), and pouches are usually emptied no more than twice daily.

When to Consider Enlarging an Ostomy Opening

Patients dependant on others for stoma care. Patients trying to learn ostomy care may have limited dexterity or vision, so correct placement of an ostomy pouch on the skin around the stoma is sometimes too challenging to master, especially when the stoma is difficult to visualize. Consequently, the patient is dependent on caregivers for ostomy care.

Irregular stoma shape. Patients may have difficulty accurately measuring, tracing, and cutting a pattern for a stoma with an irregular shape.

Discomfort from a convex pouch. A convex pouch, with or without an added belt, may be successful in overcoming shape or abdominal contour irregularities. However, convexity may be uncomfortable for the patient in their activities of daily living.

Enlarging stoma from a hernia. Peristomal hernias that protrude when the patient sits or stands can enlarge stomas beyond the pouch opening, causing mucosal moisture to weaken the pouch adhesive.  

Irregular peristomal or perifistula abdominal contour. Assessment of the peristomal and perifistula area with the patient supine, sitting, and standing may reveal skin creases, depressions, or incisional irregularities that can change the abdominal contour and contribute to pouch leaking. These irregularities make placement and adhesion of a pouch difficult.

Stomal stenosis and small fecal stomas. The small diameter of a stenosed stoma can contribute to explosive evacuations.14 A pouch opening cut to the size of the stenosed stoma may be too small to accommodate the force or volume of the stool passing through it. Likewise, the authors have found that pouch openings for small fecal stomas (ie, <1 inch) may be too small to accommodate the volume, force, or size of stool evacuation.

Case Studies Illustrating Enlarging The Ostomy Opening

Case 1. Ms. A, a healthy 75 year old, developed an intestinal obstruction and had surgery with construction of a descending end colostomy. Upon discharge from acute care, she went to her son’s home to recuperate and was followed by a home health agency. She used a 1-piece transparent flat pouch. Her daughter-in-law managed her ostomy care, but Ms. A wanted to be independent so she could return home as soon as possible. At 6 weeks postop, she had a slightly irregular, oval, moist, red, bud stoma, 1 inch long x 1¼ inch wide. Her bowel movements consisted of formed stool, once daily. Her peristomal contour was flat when she was supine, sitting, and standing.

When Ms. A tried to learn ostomy care, she had difficulty cutting the pouch opening to the shape of her stoma and also had difficulty seeing well enough to correctly position her ostomy pouch around the stoma. She often placed the pouch on a portion of the stoma mucosa, which caused premature leakage and required more frequent pouch changes.

Interventions and outcome. The CWOCN instructed Ms. A to place a barrier ring on her skin close to the stoma (see Figure 1a). Mrs. A could check placement of the ring with a mirror and if it was not positioned correctly, she was able to lift and reposition it without difficulty until the peristomal skin was completely protected with the ring. A round, 1¾-inch opening was cut in the pouch. Because the peristomal skin was protected by the skin barrier ring, exact placement of the ostomy pouch was not critical. The enlarged opening on the ostomy pouch could be placed anywhere on the skin barrier ring, as long as the stoma was not covered (see Figure 1b).

Using this technique, Ms. A quickly became independent in her ostomy care and no longer had to depend on her family for assistance. She moved back home and was able to independently change her pouch twice weekly using a 1¾ inch precut pouch, which made the process even easier.

Case 2. Healthy, 65-year-old Mr. B presented to the WOC nurse clinic at a community hospital. He was post radical cystectomy and had an ileal conduit/Bricker urinary diversion for bladder carcinoma. This surgery had been performed at a nearby medical center; his pouch — a convex pouch with an opening 3/32 inch larger than the stoma, with an integrated extended wear skin barrier backing and a belt — had been selected immediately postoperatively by the Center’s WOC nursing team. His wear time was 3 days or less. His chief complaint was discomfort from the rigid faceplate and belt.

On examination, Mr. B was noted to have a 7/8 inch round x ¼ inch high stoma that was hidden in a skin fold when he was in the sitting position (see Figure 2a). The stoma could only be visualized if the skin fold was lifted (see Figure 2b).

Interventions and outcome. The CWOCN instructed Mr. B and his wife to cut a flexible pouch with a transparent film backing 1 inch larger than the stoma size, apply skin cement to 2 inches on the skin around the stoma (see Figure 2c) and 1 inch on the pouch around the opening (see Figure 2d); wait for the cement to dry; and apply the pouch over the stoma (see Figure 2e). Mr. B returned to the nursing clinic 1 month later; he was able to wear the new pouch for 7 days. He had no leakage and his skin was intact. Mr. B immediately noted increased comfort without the convexity and the belt. He was able to decrease the cost of his pouching supplies from $125.77 to $38.31 per month.

Case 3. Ms. C was a 94-year-old woman with a loop colostomy for 7 months due to a ruptured diverticulum. She was considered a problem resident by the staff at her assisted-living facility (ALF) because her ostomy pouch usually required twice-daily changes. The staff insisted that she picked at the pouch, loosening it and causing it to leak. She also was followed by a home health agency. The staff always performed her ostomy care when Ms. C was supine. In this position, the stoma was 1¾ inches long x 1¾ inches wide, slightly raised, moist, and red, with a flat peristomal area (see Figure 3a). When the CWOCN asked Ms. C to sit and stand, she developed a large peristomal hernia that significantly enlarged the size of her stoma to 3½ inches long x 2½ inches wide, with a depression at the 6:00 o’clock position where the appliance usually leaked (see Figure 3b). Ms. C had peristomal medical adhesive-related skin injury (MARSI) because the enlarging hernia caused skin stripping from the adhesive on the pouch backing. The MARSI caused itching that Ms. C frequently scratched. Additionally, her enlarged stoma extended beyond the wafer opening, so moisture from the stoma mucosa weakened the seal. The challenge was to find a flexible large appliance to accommodate the changes in stoma size and abdominal contours that occurred with position changes.

Interventions and outcome. The CWOCN for the home health agency arranged for a meeting with the ALF staff in the patient’s room to educate them on changes to the pouching procedure. Using a large, 2-piece pouch with a flexible adhesive flange, an opening was cut to the size of stoma that expanded when sitting or standing (see Figure 3c and Figure 3d). Skin barrier powder and a moisture insoluble skin barrier were applied in 3 alternating layers to the exposed peristomal skin for protection. A skin barrier strip was molded and tapered to the back of the pouch at the 6:00 o’clock position to accommodate the depression that developed with position change.

Using this new procedure, the ostomy pouch was changed every 3 days by the ALF staff. The peristomal skin remained intact, and Ms. C did not disturb the pouch. The MARSI and peristomal itching resolved, so Ms. C stopped scratching her skin. She was no longer considered a problem patient by the ALF staff.

Case 4. Seventy-five-year-old Ms. D was undergoing treatment for metastatic ovarian cancer. Following her complicated surgery (that included colon resection), she returned home with a heavily draining enterocutaneous fistula and instructions to change an ABD pad dressing 6 times a day. The dressing change was very time-consuming and painful due to skin breakdown from the liquid effluent and frequent tape removal. Attempts to use a pouch with the opening cut to the size of the fistula consistently failed within a few hours after placement. The liquid effluent followed a depression in the skin and broke the seal. Like many fistulas, Ms. D’s had deep crevices in her skin from scars, and irregular perifistula abdominal contours had developed as the wound healed. Ms. D depended on her family and a caregiver to provide her care.

Interventions and outcome. Although fistulas are not ostomies, clinicians use the same products and principles to contain effluent. The home care CWOCN instructed the caregiver on how to protect the perisfistula skin using 3 alternating layers of skin barrier powder and a moisture-insoluble skin barrier (see Figure 4a) and using skin barrier paste and strips to fill the perifistula creases (see Figure 4b). A fistula pouch was cut with the opening large enough to bypass the numerous creases and depressions surrounding the fistula. Skin barrier paste was placed around the pouch opening, and the pouch was applied to the level perifistula abdominal plane (see Figure 4c). Mrs. D’s paid caregiver, who came to her home on weekday mornings, quickly learned the pouch change procedure as instructed by the CWOCN. Ms. D’s fistula pouch was changed Mondays, Wednesdays, and Fridays without leaking. Ms. D appreciated the extra time she had to spend with her family and her improved quality of life.

Case 5. Ms. E, 62 years old, developed a pelvic mass and was diagnosed with metastatic ovarian cancer. She had surgery for a total hysterectomy, colon resection, and colostomy with a Hartman’s pouch. Her postsurgical recovery was complicated by pleural effusion and respiratory failure. Ms. E was admitted to home care services 3 months post op with some memory deficit. She had a very stenosed stoma in her right lower quadrant that measured ¼ inch long x 3/8 inch wide, and her stool was liquid to mushy. Her peristomal area was flat when she was supine, but her stoma retracted with sitting and standing. Ms. E used a 2-piece, flat transparent pouch; she could remember to change her pouch every 3 days but she had difficulty comprehending that her pouch should be changed if the seal loosened, which was usually 1 day after a new pouch was placed. Consequently, she had peristomal skin breakdown from stool leakage.

Interventions and outcomes. Ms. E’s care involved several factors: her difficulty comprehending that she needed to change her pouch when it leaked, the potential for pouch leakage from forceful evacuations due to the stenosis,14 and a retracted peristomal plane around the stoma with position change. The CWOCN instructed her to protect her peristomal skin with skin barrier powder and moisture insoluble skin barrier, then cut her pouch opening to 1¼ inch round. The larger opening allowed for any potential increased force or volume of effluent and bypassed the retracted area that caused stool to leak under the wafer during position change. In addition, the larger pouch opening was easier for Ms. E to place. She continued to change her ostomy pouch every 3 days, and there was no leakage. Her peristomal skin healed, and she became independent in her ostomy care.


Florence Nightingale was adamant that nursing schools should provide training in both the art and science of nursing. “To Nightingale, the purpose of her school was to create for nurses a respected profession combining both ‘art and science’ as well as an opportunity to serve God by serving mankind.”15 WOC nurses who successfully assess needs and teach patients how to pouch challenging stomas practice the art of nursing.

Traditional ostomy guidelines recommend cutting the pouch opening no more than 1/8 larger than the size of the stoma to protect the peristomal skin, but in the 6 circumstances described and in the 5 case studies presented, assessment determined the need for pouch openings larger than 1/8 inch beyond the stoma. Various products were used to protect the exposed peristomal skin, including moisture insoluble skin barrier sprays or wipes, skin barrier rings, skin cement, skin barrier powder, skin barrier strips, and skin barrier paste. The authors also used transparent film dressings, moisture-insoluble hydrocolloid dressings, and solid skin barriers to protect peristomal and perifistula skin. In each case, product wear time improved. In case 4, the pouch used on the fistula was more expensive than the ABD pads, but changing the fistula pouch 3 times weekly was less time-consuming and more acceptable to the patient than changing ABD pads 6 times daily. In all of the other cases, supply costs and usage decreased while wear time improved, and in every case, patient satisfaction improved.


Although initial ostomy care should include a pouch opening no more than 1/8 inch beyond the stoma edge, these cases present circumstances when alternative products were used to protect peristomal skin, and pouch openings were larger than 1/8 inch, allowing wear time to increase, product usage and cost to decrease, and patient satisfaction to improve. Clinicians caring for patients with ostomies who experience premature pouch leakage or self-care deficits might consider a larger pouch opening while protecting exposed peristomal skin with alternative products.


Ms. Green is a wound, ostomy, continence nurse, HomeCall, Inc, Frederick, MD. Ms. Faller is a wound, ostomy, continence nurse in private practice, Turner Falls, MA. Ms. Lawrence is a wound, ostomy, continence nurse, Rutland Area VNA and Hospice, Rutland, VT.


Please email correspondence to: Mary Green, BSN, RN, CWOCN:


This article was not subject to the Wound Management & Prevention editorial review process.