A mucous fistula is a surgically created opening on the abdomen following certain bowel diversion procedures. It is a necessary result when the intestine is completely divided into two separate ends, typically formed alongside an end colostomy or end ileostomy. Although the term “fistula” often suggests an abnormal connection, the mucous fistula is intentionally constructed to manage the non-functioning segment of the digestive tract.
Defining the Mucous Fistula
The creation of a mucous fistula involves separating the bowel into two distinct sections: the proximal, or upstream, segment and the distal, or downstream, segment. The proximal segment is the “working” end, which is brought out through the abdomen to form the stoma that passes stool and gas. The distal segment, which is no longer connected to the flow of digested food, is externalized to create the mucous fistula.
This distal segment, which remains attached to the rectum or anus, continues to perform its normal physiological function of producing mucus and sloughing off cells. Since the body constantly produces this intestinal secretion to protect the lining of the bowel, the mucus needs a safe exit point. Without the mucous fistula, this material would accumulate in the bypassed segment, potentially leading to a buildup of pressure or a rupture inside the abdomen.
The mucous fistula is often referred to as a “distal stoma.” It acts solely as a vent for secretions and gas, distinguishing it from the functional stoma that processes solid waste. This planned surgical bypass is used in procedures for conditions like inflammatory bowel disease, colorectal cancer, or severe diverticulitis.
Clinical Context and Appearance
A mucous fistula generally presents as a smaller, flatter opening on the abdominal wall compared to the primary working stoma. It is typically moist, pinkish-red, and should be relatively flush with the skin surface, though the exact appearance varies by surgical technique. The fistula is much smaller than the adjacent functional stoma, which is designed to accommodate the passage of solid or liquid waste.
The expected output is predominantly mucus, usually clear, pale yellow, or white in color. This discharge may contain a small amount of gas but should not contain stool, as the segment is diverted from the main digestive flow. While output may be high initially, the volume generally decreases significantly over the weeks and months following the surgery.
While the mucous fistula is designed to be low-maintenance, certain changes in appearance warrant immediate medical attention. Signs of compromised blood flow, such as a dark purple or black coloration (ischemia or necrosis), indicate a serious complication. Excessive or persistent bleeding, or any sudden changes in the fistula’s shape (retracting or dramatically protruding), should be evaluated by a healthcare professional.
Management and Care
The care requirements for a mucous fistula are typically far less involved than those for the primary working stoma. Due to the minimal and non-irritating nature of the mucus output, many people can manage the site with simple absorbent coverings. A small piece of gauze, a non-adhesive dressing, or a specialized stoma cap is often sufficient to collect the discharge.
If the output is initially high or particularly irritating, a smaller pouching system may be necessary for a short period. A specialized stoma nurse provides detailed instructions on selecting the correct appliance and protecting the surrounding skin. Regular cleaning with mild soap and water helps maintain skin integrity and prevents irritation from moisture.
Monitoring the mucous fistula for proper drainage is important. A complete lack of output over a prolonged period, accompanied by abdominal pain or swelling, could suggest an obstruction in the bypassed segment. Conversely, a sudden increase in output that is watery or foul-smelling may indicate a change in the underlying condition. Consistent communication with a surgeon or ostomy nurse ensures that any changes are addressed promptly.