What Fruits Cause Red Stools? A Guide to Dietary Discoloration

December 9, 2025 •

4 min read

Seeing red in the toilet can be an alarming sight, but studies show that up to 90% of red stools are caused by something other than blood. Before panicking, it’s worth considering your recent diet, as a surprising number of common fruits can cause red stools, a temporary and completely harmless phenomenon.

Quick Summary

Learn which common fruits, including beets, cranberries, and tomatoes, can temporarily turn your stool red due to natural pigments and how to distinguish this from more serious issues.

Key Points

Beets are the most common cause: The pigment betanin in beets is a frequent, harmless cause of reddish stool and urine.
Red fruits contain undigested pigments: Lycopene in tomatoes and anthocyanins in berries can pass through the digestive system and color stool red.
Dietary discoloration is temporary: Color changes from fruit typically resolve within a day or two after the food is no longer consumed.
Bleeding has key differences: Unlike dietary color, bloody stools are often accompanied by other symptoms like pain or weakness, and the color may be bright red or dark and tarry.
Consult a doctor if symptoms persist: If red stool continues for several days, is accompanied by pain, or has no clear dietary cause, it's best to seek medical advice.
Fast digestion can enhance color: A high-fiber diet can speed up digestion, allowing less time for pigments to break down and making them more visible in the stool.

The Science of Fruit-Induced Red Stools

The color of our stool is influenced by what we eat and drink. When the body consumes foods with strong pigments that are not fully absorbed or broken down during digestion, these pigments can pass through the digestive tract and appear in the stool. This is particularly common with fruits containing vivid red or reddish-purple pigments, which can survive the digestive process largely intact.

Key Pigments at Play

Betanin (from Beets): Beets contain a potent reddish-purple pigment called betanin. The presence of this pigment in urine or stool is known as 'beeturia,' and it's a common and harmless occurrence for 10–14% of the population, especially after consuming a large amount of beets.
Lycopene (from Tomatoes and Watermelon): Tomatoes and watermelon are rich in lycopene, a red carotenoid pigment. While not everyone is sensitive to it, consuming large quantities of tomato products (sauce, juice) or watermelon can be enough for the pigment to show up in your stool.
Anthocyanins (from Berries and Rhubarb): Many red and purple berries, like cranberries and blackberries, contain anthocyanins. These pigments can sometimes pass through the digestive system without being completely broken down, especially when transit time is fast. Rhubarb, often used in fruit-like desserts, also contains compounds that can cause red or reddish-brown stools.

Factors Influencing Pigment Appearance

How much of the pigment appears in your stool can depend on several factors, including your individual digestive system, the amount of fruit consumed, and even your body's pH levels. If food moves through your system faster than usual, perhaps due to high fiber intake or other digestive factors, the pigments have less time to be broken down, making their presence more noticeable.

Fruits That Can Cause Red Stools

The following fruits and fruit-based products are the most common dietary causes of harmless red stools:

Beets: The most well-known culprit. Even a small portion can result in reddish stool and urine.
Cranberries: Consuming a large amount of fresh cranberries or cranberry juice can lead to red-tinged stool.
Tomatoes: High quantities of tomato juice, soup, or a large amount of raw tomatoes can be the cause. The skins can also appear as red flecks.
Rhubarb: This vegetable, which is often prepared like a fruit, contains pigments that can turn stool red.
Blackberries and Blueberries: These dark berries can sometimes cause stools to appear reddish or even blackish, though the color is typically very dark.
Watermelon: This fruit is a source of lycopene, and a large portion can sometimes lead to a reddish hue in stool.

Is It Dietary or Blood? How to Tell the Difference

While seeing red stools can be concerning, it's crucial to distinguish between harmless dietary effects and potentially more serious medical issues involving gastrointestinal bleeding. The following table provides a quick comparison to help you assess the situation.


Characteristic	Dietary Cause (Fruit Pigments)	Medical Cause (Bleeding)
Appearance	Color often pinkish, maroon, or reddish-brown. Sometimes has visible, undigested fruit particles. Color may be inconsistent.	Color can be bright red (lower GI bleed) or dark, tarry black (upper GI bleed). Consistency may also change.
Onset	Occurs shortly after consuming a large amount of a colored fruit or food.	Can occur without any specific dietary trigger.
Duration	Usually resolves within 1-2 days after discontinuing the offending food.	Persists or worsens over several days.
Accompanying Symptoms	Typically none, aside from the color change.	May include abdominal pain, weakness, dizziness, diarrhea, or fever.

When to Consult a Doctor

While dietary red stools are generally not a cause for concern, it is always wise to be cautious. You should contact a healthcare provider if:

The red stool persists for more than a few days after you stop eating the suspected fruit.
You cannot link the red color to any specific food or medication you have consumed.
You experience additional symptoms, such as abdominal pain, nausea, vomiting, fever, or unexplained weight loss.
The stool is black and tarry, which can indicate bleeding higher up in the digestive tract.
There are large clots or a significant volume of blood in the stool.

For more detailed information on rectal bleeding, the Cleveland Clinic offers comprehensive resources covering various potential causes and when to seek medical attention. Rectal Bleeding (Blood in Stool): Causes, Colors & Treatments.

Conclusion

Many people experience harmless changes in stool color due to their diet, and several fruits with strong pigments are common culprits. Beets, cranberries, tomatoes, and certain dark berries are all known to cause red stools. The key to determining whether the color is benign or a sign of a health issue is to observe for any accompanying symptoms and note how long the discoloration lasts. When in doubt, a quick call to your doctor can provide peace of mind and rule out any serious underlying conditions.

Frequently Asked Questions

Red discoloration in stool from eating beets, a phenomenon known as 'beeturia', is temporary and usually clears up within 1 to 2 days after you stop consuming beets.

Red stool caused by food is typically temporary and has no other symptoms. Blood in stool often persists, may be accompanied by abdominal pain, dizziness, or weakness, and the color can range from bright red to dark and tarry depending on the source.

Yes, artificial red dyes, such as Red 40 found in candy, gelatin, and cereals, are known to cause red-colored stools. This is also a harmless, temporary effect.

Yes, especially with high-fiber fruits. Undigested parts, like tomato skins or fragments of berries, can appear in the stool, contributing to its reddish appearance.

Yes, consuming large quantities of cranberry juice can cause your stool to appear reddish due to the natural pigments in the fruit. This is typically a harmless, temporary effect.

If you are certain the discoloration is from a fruit you've eaten and there are no other concerning symptoms, there is no need to stop eating it. If you are unsure, you can temporarily remove the suspected food from your diet to see if the color returns to normal.

While not a fruit, iron supplements can cause stools to become dark green or even black. It is important to distinguish this from the reddish hue of beets or red food coloring.