SELF/Colostomy

   ⚠️In Development: Module actively being built.

▼This page is a part of the Anesthesia and Critical Care Curriculum by WACS and SELFPlease see the Intuitive Foundation Terms of Use and do not edit without permission.

Developer instructions

Summarize key lessons covered in the knowledge materials and outline any contextual information required for the learner.

Teaching the trainee the principles of loop colostomy including anatomical landmark identification, stoma maturation, and avoiding common complications.

Developer instructions: create an assessment page

Self-assessment

Please complete the following: Quiz

Developer instructions

Summarize key lessons covered in the knowledge materials and outline the skills or outcomes learners are expected to gain by the end. Work on this section after completing section 4.3 in the worksheet.

• Describe the major indications and contraindications for performing a loop colostomy.
• Explain the essential elements of informed consent, including complications and lifestyle implications.
• Enumerate the essential instruments and preoperative preparations, including site marking and anesthesia considerations.
• Outline the sequence of surgical steps in creating and maturing a loop colostomy.
• Differentiate between loop and end colostomy in terms of purpose, function, and risks.
• Recognize the importance of adequate postoperative conditions and patient suitability in decision making.

A colostomy is a surgically created opening between the colon and the abdominal wall that allows fecal matter to exit the body into an external collection device, bypassing the distal bowel and rectum. The opening, called a stoma, is typically fashioned on the anterior abdominal wall, most often in the left lower quadrant. Depending on the clinical situation, the stoma may be temporary—used to divert fecal flow while the distal bowel heals—or permanent, when the rectum or distal colon must be removed or excluded. Colostomies can be fashioned as either a loop, in which a segment of bowel is brought out with both proximal and distal openings, or as an end colostomy, where only the proximal bowel is exteriorized.

The primary purposes of a colostomy are to relieve distal obstruction, divert stool from areas of injury or infection, and protect newly constructed bowel anastomoses. The stoma should protrude above the skin and remain well vascularized to allow effluent to empty directly into an attached appliance, thereby minimizing contamination of surrounding skin. While lifesaving and functionally effective, a colostomy carries significant lifestyle implications for the patient, including the need for long-term stoma care, potential skin complications, and psychological adjustment to altered body image. For these reasons, careful preoperative planning, appropriate patient counseling, and precise surgical technique are essential to achieving good outcomes.

Loop colostomy is most often performed in the context of large bowel obstruction, perforation, or as a diversion in cases where distal healing needs to be protected. Practitioners must recognize the classic indications such as obstructing rectosigmoid carcinoma, penetrating or blunt trauma requiring fecal diversion, or severe perianal sepsis where fecal flow through the distal colon must be temporarily bypassed. Loop colostomy is also frequently used as a temporizing measure in inflammatory conditions such as fulminant diverticulitis or Crohn’s disease with perforation, and in cases of rectal injury from obstetric trauma. Temporary diversion is important in patients with high-risk pelvic anastomoses where leakage could be catastrophic.

Contraindications should be equally well appreciated. A loop colostomy is generally avoided in patients who cannot tolerate abdominal surgery due to severe cardiopulmonary instability, in the presence of generalized peritonitis requiring resection and exteriorization instead, or when the colon proximal to the proposed site is diseased or ischemic. Practitioners must also consider patient-specific anatomical challenges, such as severe obesity or distorted abdominal wall anatomy from previous surgery, which can make creation of a viable, easily manageable stoma difficult. It is important to recognize that in patients with advanced malignancy and very limited life expectancy, a stoma may not improve quality of life and may even complicate care, in which case alternative palliative measures may be more appropriate.

The decision to proceed with a loop colostomy must integrate both the immediate surgical necessity and the downstream effects on patient management. For instance, while the procedure may relieve obstruction quickly, it must be considered whether the patient will be able to manage stoma care postoperatively. This requires anticipating lifestyle impact, family support, the availability of clean supplies, and the ability to maintain a hygienic postoperative environment. A poorly considered stoma indication can result in significant morbidity, including skin breakdown, prolapse, or recurrent sepsis.

In summary, practitioners should weigh the urgency of fecal diversion against long-term considerations such as patient suitability for stoma care, likelihood of reversal, and the technical feasibility of alternative procedures.

Informed consent for loop colostomy requires a frank and detailed discussion with the patient or family, emphasizing both the immediate goals and the long-term implications. The patient should understand why a colostomy is needed—relief of obstruction, protection of an anastomosis, or diversion from an infected or injured area—and what alternatives, if any, exist (primary resection with anastomosis, Hartmann’s procedure, endoscopic stenting). They should be explicitly informed that in many cases the procedure is temporary, but in some contexts, it may become permanent if reversal proves unsafe or unfeasible. This clarity is critical to reduce postoperative distress and resentment.

The discussion must also cover possible complications. These include stomal complications such as prolapse, stenosis, retraction, and parastomal hernia, as well as general operative risks like bleeding, wound infection, and anesthesia-related events. The potential impact on body image, lifestyle, and daily function—including the need for stoma appliances, changes in clothing, and possible restrictions on activity—should be addressed without minimizing these challenges. Patients must also be made aware that stoma care requires regular supplies and basic hygiene, and failure to maintain these can lead to skin excoriation and infection.

Anesthesia is another critical point. The patient should be told whether general or spinal anesthesia is planned, and why. Patients with comorbidities such as severe chronic lung disease or advanced heart failure may benefit from avoiding general anesthesia when possible, and these considerations should be explained openly. The risks of anesthesia should be presented in the context of their overall condition, along with the safeguards in place, such as intraoperative monitoring and postoperative pain management.

Finally, the patient must be counseled on postoperative care and recovery. This includes the expected duration of hospitalization, the timeline for return of bowel function, and the plan for follow-up visits. Importantly, they should understand the impact on lifestyle: diet modifications, the need for ongoing medical review, and possible long-term adaptations if the stoma becomes permanent. Informed consent must move beyond a signature on a form to a process of ensuring patient comprehension and alignment with their own goals of care.

Self-assessment

Please complete the following: Pre-procedure Quiz

The operative field requires IV access secured preoperatively, insertion of a nasogastric tube, and placement of a Foley catheter before anesthesia induction. The laparotomy set should be laid out with the scalpel and retractors positioned at the top of the Mayo stand, followed by electrocautery, bowel clamps, Babcock graspers, and suction tubing. Sutures, both absorbable and non-absorbable, should be checked for availability, and ostomy-specific equipment such as a stoma template, skin marker, and the appliance system should be prepared and within easy reach. Drapes and antiseptic prep solutions must be opened only after ensuring sterility and sequence of use.

Stoma site marking is another essential step. This must be done with the patient awake, in both sitting and standing positions, to avoid placement in skin folds, over bony prominences, or in areas where clothing or belt lines would interfere. The left iliac fossa, above the waistline and within the patient’s line of sight, is most often selected. The surgeon should use the stoma template to confirm that the site is flat and accessible, avoiding locations near scars or creases that might compromise appliance adhesion. Failure to carefully mark the site preoperatively is one of the most common causes of poor postoperative stoma function.

Choice of anesthesia depends on patient factors. General anesthesia offers maximal control, particularly for patients with multiple comorbidities, but spinal anesthesia may be preferred for high-risk cardiopulmonary patients if abdominal relaxation can be achieved - see Spinal Anesthesia module. Preoperative evaluation must include optimization of fluid status, correction of electrolyte abnormalities, and prophylactic antibiotics given within one hour of incision. Practitioners should also ensure warming devices are available to maintain normothermia, as hypothermia increases risk of wound infection and coagulopathy.

Finally, the surgical team must confirm the operative plan, including whether a loop or end colostomy is intended, and whether a midline laparotomy or localized stoma-site incision will be used. Patient positioning should be supine with arms padded and secured, ensuring that the chosen stoma site remains accessible after draping. The abdomen should be widely prepped from nipple line to mid-thigh, laterally to the table edges, to permit conversion to a midline laparotomy if required.

The surgical approach depends on the indication and intraoperative findings. For cases requiring full exploration, a vertical midline laparotomy from the umbilicus to the pubis provides optimal exposure. The incision should be made decisively with a scalpel, followed by layered entry using electrocautery and retractors. The peritoneal cavity is inspected, bowel loops are examined, and the target segment—usually sigmoid colon—is identified and mobilized with Babcock forceps and gentle electrocautery dissection. Care should be taken to avoid excessive traction on the mesentery, which risks vessel injury and devascularization.

When only fecal diversion is needed and no exploration is required, the incision may be made directly at the pre-marked stoma site. A circular 3–4 cm incision is carried through the skin and subcutaneous tissue, then the rectus sheath is divided in cruciate fashion, and the rectus muscle fibers are separated bluntly. The peritoneum is opened just enough to accommodate the loop without constriction, avoiding the deep inferior epigastric vessels. An opening that is too small risks ischemia of the delivered bowel, while one that is too large leads to weak abdominal wall support and predisposes to parastomal hernia.

The loop of colon is then gently delivered through the opening using Babcock forceps, ensuring no torsion and that the mesentery is not excessively tight. The bowel should sit without tension and with adequate blood supply confirmed by color and peristalsis. In the case of a loop colostomy, a supporting rod or catheter may be passed through the mesenteric window beneath the loop to prevent retraction. The antimesenteric border is then incised, and the bowel edges are everted and sutured to the skin in a secure but non-strangulating fashion. Proper maturation ensures that the stoma protrudes adequately to direct effluent into the appliance without leakage.

Decision making regarding loop versus end colostomy must occur intraoperatively if unexpected findings arise. A loop colostomy brings a loop of colon to the surface with both proximal and distal openings, usually used for temporary diversion to relieve obstruction or protect a distal anastomosis; it preserves continuity but carries risks of prolapse, retraction, and leakage if not matured properly. An end colostomy exteriorizes only the proximal colon after resection or exclusion of the distal bowel, often permanent in malignancy or severe distal disease, providing more secure diversion but with higher impact on lifestyle and risk of parastomal hernia. For example, if a resectable tumor is identified or if the distal bowel is unsalvageable, a loop may not provide definitive care and an end colostomy should be created instead. The surgeon must be prepared to adjust the plan, weighing the immediate safety of the patient against long-term oncologic or functional outcomes. This capacity to adapt in real time reflects both sound surgical judgment and mastery of operative technique.

In low resource environments, shortages of specialized equipment and personnel may require adaptation. If stoma appliances are scarce, practitioners should still mark and fashion the stoma carefully, as correct placement reduces the risk of leaks even with improvised collection devices. In the absence of a formal stoma rod, a soft Foley catheter or similar sterile tubing can be used to support the loop and prevent retraction. When advanced electrocautery is unavailable, sharp dissection with scalpel and scissors, combined with meticulous hemostasis using sutures or ties, remains safe and effective.

Where anesthetic options are limited, careful assessment of patient comorbidities is crucial. If general anesthesia with monitoring equipment is unavailable, spinal anesthesia may be used provided abdominal relaxation is sufficient. Surgeons should remain mindful of fluid shifts, electrolyte abnormalities, and hypothermia, and compensate with vigilant monitoring and simple supportive measures. Above all, in resource-limited contexts, surgical decision making must prioritize safety, selecting the simplest effective option that avoids complications the team is not equipped to manage.

Self-assessment

Please complete the following: Surgical Procedure Quiz

Cumulative Test

Please complete the following: Colostomy Module Test

Developer instructions

Complete with knowledge materials broken up by lesson / topic.

Developer instructions: create an assessment page

Self-assessment

Please complete the following: Quiz

Developer Instructions

In a brief paragraph or two, describe your simulator. What does it look like? What does it do? What are the layers or elements? Work on this section after completing the simulation requirements

• BUILD INSTRUCTIONS
• PRACTICE INSTRUCTIONS

• Link: [Description]
• Link: [Description]

• Link
• Link

Developer Instructions

Include any research or sources you used to develop this module that may be helpful to learners. You may also add evidence demonstrating the module’s impact or effectiveness.

• Link: [Description]

• Link: [Description]