Observing a change in stool color can be a cause for concern, especially when it appears reddish. While an altered stool color can sometimes signal a health issue, it is often a harmless result of dietary intake. Many people wonder if common foods, like tomato sauce, can lead to red stool, and understanding the reasons behind such changes can alleviate unnecessary worry.
Tomato Sauce and Red Stool
Tomato sauce can cause stool to appear reddish. This occurs due to lycopene, a red pigment in tomatoes. Lycopene is a carotenoid, a phytonutrient responsible for colors in many fruits and vegetables.
When you consume tomato sauce, lycopene may not be fully absorbed during digestion. This undigested pigment passes through the gastrointestinal tract and can impart a reddish hue to the stool. This is a normal physiological response and not a sign of a health problem. You might even notice small red pieces of tomato skin or pulp in the stool, indicating its dietary origin.
Other Foods That Can Alter Stool Color
Food altering stool color extends beyond tomato sauce. Many other foods and beverages contain strong pigments or artificial dyes that resist digestion and change stool color. These changes are benign and temporary.
For instance, consuming beets can lead to reddish or pinkish stools due to betacyanin pigments. Artificial food colorings, found in red gelatin, red velvet cake, candies, and certain drinks, can also cause vivid red or orange stools. Cranberries and red peppers are examples of foods whose pigments or undigested fibrous components can make stool appear reddish.
When Red Stool Is Not Just Food
While food-induced red stool is common, red stool can also indicate blood. The appearance of blood in stool varies significantly depending on its source and how long it has been in the digestive tract. Distinguishing between food-related discoloration and blood is important for determining if medical attention is needed.
Bright red blood in the stool, hematochezia, suggests bleeding from the lower gastrointestinal (GI) tract, such as the colon, rectum, or anus, and can appear as streaks on the stool, drops in the toilet bowl, or mixed with the stool itself. Hemorrhoids, anal fissures, or diverticulosis are common causes of bright red rectal bleeding. In contrast, very dark red or maroon-colored stool indicates bleeding from higher up in the colon or small intestine, where blood has had more time to be partially digested. Black, tarry, and foul-smelling stools, known as melena, signify bleeding from the upper GI tract, such as the stomach or esophagus, because the blood has been digested. Food-related red stool, however, lacks the tarry consistency or foul odor associated with digested blood and may still show visible food particles.
Knowing When to Consult a Doctor
While many instances of red stool are harmless and diet-related, certain signs and symptoms accompanying a change in stool color warrant medical evaluation. Consult a healthcare professional if you experience persistent red stool not clearly linked to dietary intake, or if the stool appears black and tarry.
Additional symptoms that signal a need for medical attention include severe abdominal pain or cramping, unexplained weight loss, fever, or persistent vomiting. Signs of anemia, such as unusual fatigue, pale skin, dizziness, or shortness of breath, when accompanied by red or dark stools, also indicate potential internal bleeding requiring medical assessment. If you are taking blood thinners and notice red or black stools, seeking medical advice is particularly important. Any significant amount of bright red blood, especially if accompanied by lightheadedness or a rapid heartbeat, should prompt immediate emergency care.