Finding blood and mucus in a baby's stool is understandably alarming. Obvious blood usually indicates bleeding from the lower part of the baby's digestive tract. However, what may look like blood is sometimes a harmless color change related to the baby's recent diet. Some mucus in the stool is normal, but an excess amount accompanied by blood may be a sign of infection or another digestive system problem. Call your doctor right away if your baby has bloody stool, with or without mucus.
Infections caused by certain bacteria -- such as Salmonella, Shigella or E.coli -- or small parasites commonly lead to blood and mucus in the stool. Babies with these infections usually have diarrhea, but the stool may be formed in some cases. The baby may also have a fever, vomiting and a tender belly. These infections are caused by eating food or drinking liquids contaminated with disease-causing germs. Treatment depends on the specific cause of the infection. Watch for signs of dehydration that can occur from diarrhea and vomiting, including excessive fussiness, sleeping more than usual, sunken eyes, an indented soft spot on the head, cool skin and fewer than 6 wet diapers per day.
Food reactions are another possible cause of blood and mucus in a baby's stool. These reactions are triggered by proteins in certain foods. Cow's milk and soy are the leading causes of food reactions in babies, but they can also occur with other foods, especially when the baby is first introduced to a new food. This type of food reaction -- known by the medical name food protein-induced enterocolitis syndrome (FPIES) -- can be serious because it may lead to dehydration and poor weight gain. The condition is treated by removing the offending food from the baby's diet.
Small Anal Tear
The tissues at the end of the bowel that allow stool to pass from a baby's body are delicate and contain many small blood vessels. Passing a hard stool sometimes causes a small tear in these tissues, leading to blood on the outside of the stool. Although excessive mucus is not typically present with this condition, you may not have noticed the normal mucus until discovering the blood. These tears typically heal without treatment, but your doctor may recommend dietary changes for the baby to avoid constipation.
Other Digestive Tract Problems
Intussusception is a relatively uncommon but serious cause of blood and mucus in a baby's stool. It occurs when a section of the bowel slides inside the preceding portion, causing a blockage. Typical symptoms include colicky belly pain, vomiting, diminished energy and passing stool consisting primarily of blood and mucus -- which may resemble red jelly. Other problems with a baby's digestive tract can also cause blood and mucus in the stool, such as various types of colitis. Colitis is a general term that describes inflammation of the colon, which can occur due to a variety of causes.
Warnings and Precautions
While some causes of blood and mucus in a baby's stool are easily treated, others are potentially life-threatening. For this reason, it's important to call your doctor right away if your baby passes a stool with blood and mucus. Seek emergency medical treatment if you cannot reach your doctor, or if the baby has any signs of dehydration, a high fever or passes a large amount of blood.
Reviewed and revised by: Tina M. St. John, M.D.