Is it True that the Carnivore Diet Causes Hemorrhoids? What the Research Actually Says

Medically Reviewed by Ian Nathan, MBChB, on 30th January 2026

The carnivore diet is an eating pattern that consists almost entirely of animal-based foods, eliminating fruits, vegetables, grains, legumes, nuts, and most plant-derived products.

Because this diet removes virtually all sources of dietary fiber, some people worry that it may increase the risk of constipation and, by extension, hemorrhoids. Online discussions often claim that the carnivore diet either “causes” hemorrhoids due to lack of fiber or, conversely, “cures” them by reducing bowel movements. These claims deserve careful scientific examination.

This article reviews what hemorrhoids are, how they develop, the role of fiber and bowel habits in their prevention, and whether current research supports a direct link between the carnivore diet and hemorrhoids. We also discuss practical considerations for individuals considering a zero-fiber dietary approach.

What Are Hemorrhoids?

Hemorrhoids are swollen and inflamed vascular cushions in the lower rectum or anus. They are extremely common and affect a large proportion of adults at some point in their lives. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), hemorrhoids can be internal (inside the rectum) or external (under the skin around the anus) [1].

Symptoms may include rectal bleeding, itching, discomfort, pain, and swelling. In many cases, hemorrhoids are mild and resolve with conservative measures such as dietary modification and improved bowel habits.

What Causes Hemorrhoids?

Hemorrhoids develop when there is increased pressure within the rectal veins. Common contributing factors include:

• Chronic constipation
• Straining during bowel movements
• Prolonged sitting on the toilet
• Pregnancy
• Obesity
• Low dietary fiber intake

The American Society of Colon and Rectal Surgeons notes that straining and hard stools are major contributors to hemorrhoid formation [2]. Therefore, any dietary pattern that significantly alters stool consistency or bowel frequency may theoretically influence hemorrhoid risk.

The Role of Dietary Fiber in Bowel Health

Dietary fiber is found primarily in plant foods such as fruits, vegetables, whole grains, legumes, nuts, and seeds. Fiber adds bulk to stool and helps retain water, making stools softer and easier to pass.

A meta-analysis published in the American Journal of Gastroenterology found that fiber supplementation significantly improves symptoms and reduces bleeding in patients with hemorrhoids [3]. Similarly, a large systematic review in The Lancet reported that higher fiber intake is associated with lower risk of constipation and improved bowel regularity [4].

Because the carnivore diet eliminates nearly all fiber sources, it represents a significant departure from dietary patterns typically recommended for hemorrhoid prevention.

Does the Carnivore Diet Cause Constipation?

Constipation is one of the most common concerns when fiber intake drops dramatically. However, bowel responses to very low-carbohydrate diets vary between individuals.

Some people experience constipation during the transition phase, especially if fluid intake is inadequate. Others report fewer bowel movements but do not meet clinical criteria for constipation (defined as fewer than three bowel movements per week, hard stools, or straining).

Research on low-carbohydrate diets shows mixed gastrointestinal effects. In a review of carbohydrate-restricted diets, some participants reported constipation, while others experienced no significant change in bowel function [5]. Importantly, these studies were not conducted specifically on strict carnivore diets.

Mechanisms: How Could a Zero-Fiber Diet Affect Hemorrhoids?

1. Harder Stools and Straining

Without fiber, stool bulk may decrease. In some individuals, reduced stool water content can result in harder stools and increased straining—key risk factors for hemorrhoids.

2. Reduced Stool Frequency

High-protein, low-residue diets may produce smaller stool volume. While less frequent bowel movements are not inherently harmful, straining due to hard stool increases venous pressure in the anorectal region.

3. Hydration and Electrolytes

Low-carbohydrate diets increase urinary sodium and water loss, particularly in early phases. Inadequate hydration may worsen constipation and potentially increase hemorrhoid risk if straining occurs.

Is There Direct Research Linking the Carnivore Diet to Hemorrhoids?

Currently, there are no randomized controlled trials or large cohort studies directly examining whether the carnivore diet causes hemorrhoids. Most available evidence must be extrapolated from research on fiber intake, bowel function, and constipation.

Fiber supplementation has been consistently shown to improve hemorrhoid symptoms [3], suggesting that long-term absence of fiber could theoretically increase risk in susceptible individuals. However, this does not prove that a carnivore diet inevitably causes hemorrhoids.

Other Risk Factors May Be More Important

Hemorrhoids are multifactorial. Body weight, pregnancy, genetic predisposition, occupational sitting time, and bowel habits often play a larger role than any single dietary component.

For example, obesity is independently associated with increased intra-abdominal pressure and hemorrhoid development [6]. Therefore, weight changes associated with diet may influence hemorrhoid risk in either direction.

Comparison With Evidence-Based Recommendations

Major gastroenterology guidelines recommend adequate fiber intake (typically 25-38 grams per day for adults) to promote bowel regularity and reduce hemorrhoid symptoms [7].

Dietary patterns such as the Mediterranean diet, which emphasize fruits, vegetables, legumes, and whole grains, are associated with improved gastrointestinal and cardiovascular outcomes [8].

In contrast, the carnivore diet removes nearly all recommended fiber sources. While some individuals may tolerate this without issue, it diverges significantly from established public health guidance.

Practical Considerations

Individuals who choose to follow a carnivore-style diet and experience constipation or hemorrhoid symptoms may consider:

• Ensuring adequate fluid intake
• Maintaining regular physical activity
• Avoiding prolonged straining
• Seeking medical advice if rectal bleeding occurs

Rectal bleeding should always be evaluated by a healthcare professional to exclude other causes such as anal fissures, inflammatory bowel disease, or colorectal cancer.

Conclusion

There is currently no direct scientific evidence proving that the carnivore diet causes hemorrhoids. However, because hemorrhoids are strongly associated with constipation and low fiber intake, a zero-fiber dietary pattern may increase risk in some individuals—particularly if it leads to hard stools and straining.

Established medical guidelines consistently support adequate fiber intake for bowel health. Individuals considering highly restrictive diets should weigh potential benefits against known gastrointestinal risks and consult a qualified healthcare professional, especially if symptoms develop.

References

1. National Institute of Diabetes and Digestive and Kidney Diseases. Hemorrhoids.
2. American Society of Colon and Rectal Surgeons. Hemorrhoids.
3. Alonso-Coello P et al. Fiber for the treatment of hemorrhoids.
4. Reynolds A et al. Dietary fiber and chronic disease risk.
5. Slavin JL. Carbohydrates and gastrointestinal function.
6. Johannsson HO et al. Obesity and anorectal disorders.
7. NIDDK. Eating, Diet & Nutrition for Constipation.
8. Estruch R et al. Mediterranean diet and cardiovascular risk.