A colostomy is a surgical procedure that creates an opening, called a stoma, on the abdomen to divert the colon to the outside of the body. Waste material passes through the stoma into an external collection pouch, often called a colostomy bag. Discovering blood in this pouch can cause concern, but while it may indicate a serious underlying condition, it is often linked to minor, manageable causes.
Assessing the Appearance and Source of Bleeding
When noticing blood, observe its physical characteristics, as this offers clues about its source and potential severity. Blood color is a primary indicator: bright red blood suggests a source closer to the stoma or lower gastrointestinal tract. Darker, maroon, or black blood, sometimes appearing tarry, usually indicates bleeding higher up in the digestive system, where the blood has been partially digested.
Quantity is also important, differentiating between minor specks or streaks and large volumes or clots. Light spotting or small streaks on the stoma surface are often superficial and less concerning. In contrast, a moderate to large amount of blood that consistently fills the pouch or is mixed entirely with the fecal effluent warrants immediate attention. Finally, determining the location of the bleeding is paramount: whether it originates from the stoma’s delicate mucosa, the surrounding peristomal skin, or higher up inside the bowel.
Minor and Mechanical Causes of Blood in the Bag
The stoma tissue is highly vascular, possessing a rich network of small blood vessels close to the surface, similar to the gums. This vascularity makes the stoma mucosa prone to minor bleeding from mechanical trauma or friction. Routine activities like aggressive cleaning, drying the stoma with a rough cloth, or friction from clothing can easily cause a few drops of blood.
A common mechanical cause involves a poorly fitting wafer or flange. If the opening cut into the skin barrier is too small, the tight edge can rub against the stoma, causing abrasion and minor bleeding where the stoma meets the skin. Conversely, a flange opening that is too large allows corrosive fecal output to contact the sensitive peristomal skin, leading to irritation, ulceration, and bleeding.
Another frequent, yet benign, cause is the development of stoma granulomas. These are small, raised, red bumps of over-granulation tissue that form around the stoma, typically reacting to chronic irritation or friction from the pouch. Granulomas are extremely fragile and will bleed readily when touched or rubbed during pouch changes. They are not cancerous and often respond well to simple treatments like silver nitrate application by a specialized nurse.
Serious Underlying Medical Conditions
While most instances of blood are minor, persistent or heavy bleeding can signal a serious internal or systemic health issue requiring prompt medical investigation.
For individuals with inflammatory bowel disease (IBD), such as Crohn’s disease or ulcerative colitis, bleeding may represent a flare-up in the remaining colon. This inflammation causes ulcerations and mucosal damage, resulting in blood mixed within the colostomy output.
Patients may also develop stomal varices, which are enlarged, fragile veins around the stoma, often associated with portal hypertension. This condition, typically related to severe liver disease, causes increased pressure in the portal vein system, diverting blood flow to less resistant pathways, including the veins near the stoma. Bleeding from varices can be sudden and profuse, presenting as recurrent hemorrhage difficult to stop with local pressure alone.
Bleeding, especially if dark or persistent, can also be a symptom of a new growth inside the bowel. Colonic polyps, small growths on the lining of the colon, are common and may cause intermittent blood or mucus in the effluent. Although rare, a recurrent or new malignancy at the stoma site or in the remaining colon must be ruled out, particularly if accompanied by changes in stoma size, obstruction, or unexplained systemic symptoms.
Actionable Steps and When to Contact a Healthcare Provider
For minor bleeding, such as light spotting observed during stoma cleaning, the initial response should focus on stopping the superficial flow. The stoma should be gently cleansed with warm water, and a clean, dry piece of gauze or a soft cloth should be applied with light pressure directly to the bleeding area. This compression technique is usually sufficient to stop capillary bleeding within five to ten minutes, confirming a mechanical cause.
If the bleeding continues for more than ten minutes despite gentle pressure, or if the source is clearly from inside the stoma opening, contact a healthcare provider immediately. Urgent warning signs necessitating an emergency room visit include heavy, continuous bleeding, or large blood clots filling the pouch rapidly.
Systemic symptoms accompanying the bleeding also require immediate assessment, as they suggest a serious internal issue. These signs include:
- Severe abdominal pain or cramping.
- An extended absence of output from the stoma.
- A fever or chills.
- Signs of significant blood loss, such as dizziness or feeling faint.
- If the stoma changes color to dark purple, black, or appears pale, this indicates a compromise in blood flow and is an emergency situation.