Black Mucus in Stool in Babies vs Adults

Black Mucus in Stool

Bowel mucus is a very important part of good digestive health. It serves as the engine oil of sorts to the motor of the gastrointestinal tract providing much needed lubrication, as well as a means to help trap and flush out outside invaders like bacteria. In most cases, bowel mucus isn’t visible. It simply hangs about in the intestines doing its everyday job. Sometimes however, it can be evident, normally appearing as streaks of clear or white jelly like material coating the outside of the fecal matter, or streaking it here and there. It can vary in color somewhat with yellow and green being most common behind clear and white. Black mucus in stool is the least common mucus color and it can signal underlying health conditions.

One of the most common causes of evident bowel mucus is constipation. And it can create apparent mucus sightings in infants and adults as well. When the bowels have trouble evacuating, mucus can build up and then appear in abundance when fecal matter finally passes. Constipation in itself is not a cause of black mucus in stool in adults; however, it’s not uncommon for internal hemorrhoids that can be a result of chronic constipation to play a role. Dried and old blood that has lost its bright red producing hemoglobin can create a black color that can be evident in stool mucus. This old blood can also create black specks in mucus as a result of the traveling less than fresh blood remnants.

However, while hemorrhoids are not a common cause of black mucus in stool in infants, that doesn’t mean that blood in itself is not. And infants can be subject to the same cause of black or brown mucus in stool. points out that a fissure or small anal tear can be responsible for this symptom in little ones. And, blood in the stool in infants can even be caused from a temporary bout with lactose intolerance or a food allergy as well. It’s important to note however that color plays an important role in determining where the blood has come from in the case of infants. Black mucus in stool indicates a gastrointestinal source that occurs within the body, while bright red blood conversely is usually indicative of an external source.

Infants in their very early days can experience a very common cause of black mucus in stool. It’s known as meconium, and it’s only present in the first days following childbirth, according to It’s essentially a welcome to the world gift of diarrhea as it’s passed thanks to the natural laxative help of colustrum rich breast milk. This is a very short lasting phenomenon, and is a result of bilirubin content. However, should this interestingly hued diarrhea poo last long after baby has come home from delivery, a consultation with a health care provider is a good idea.

In adults, dark brown mucus or that which is black in color can be the result of blood in the stools, and that can be very serious and should prompt swift medical attention. Essentially, the higher up in the digestive tract the problem, the darker the stool or mucus will be. There are many causes of black to dark brown mucus in the stool that is related to blood in the fecal matter, and WebMD points out that it’s often a result of bleeding somewhere within the digestive tract. This can means that colitis, diverticular disease and peptic ulcers can all be to blame. Unfortunately, there are more ominous causes of black mucus in stool that are found in adults, and one of them is colon cancer (also known as bowel cancer).

It’s very important that regardless of age, if black mucus appears in fecal matter that health care be sought out promptly. Because of the potentially serious health concerns that can be related to tinges of black in the feces, it’s likely that further testing will be needed to determine the underlying cause. Since the black color is often associated with blood coming from within the body, regardless of the nature or cause, ruling out serious health hazards like cancer should be a priority.