Will Diarrhea Cause Hemorrhoids?

Diarrhea does not cause hemorrhoids in the way most people assume. Hemorrhoids are swollen veins in the rectum and anus, and the research points to pressure and straining — not loose stool — as the main trigger. That said, frequent diarrhea can irritate existing hemorrhoids and make symptoms worse. So the relationship is real, but it runs in a different direction than many people think.

What Are Hemorrhoids, Exactly?

Hemorrhoids are clusters of veins in the anal canal. Everyone has them. They help cushion the area and assist with bowel control. They only become a medical issue when those veins swell, stretch, or become inflamed.

Doctors classify them in two ways. Internal hemorrhoids sit inside the rectum, above the point where pain nerves are dense. They often bleed but rarely hurt. External hemorrhoids sit just outside the anal opening, under skin that is rich in pain fibers. These can hurt, itch, and swell.

The cushioning veins in the anal canal are supported by connective tissue. Over time, or under repeated pressure, that supporting tissue can weaken. The veins then bulge. This is why hemorrhoids become more common with age — not because of any single bowel movement, but because of cumulative pressure over years.

Will Diarrhea Cause Hemorrhoids?

No — diarrhea is not a direct cause of hemorrhoids. The evidence consistently points to chronic straining and increased pressure in the anal canal as the primary mechanism. Loose stool does not create that kind of pressure.

But diarrhea is not innocent either. Frequent, urgent bowel movements mean more trips to the bathroom and more wiping. Both can irritate the sensitive tissue around the anus. If you already have hemorrhoids, diarrhea can make them flare. The irritation is real. The cause is not.

There is one important exception worth understanding. When diarrhea is chronic — lasting weeks or longer — the constant fluid and friction can inflame the anal lining. Some clinicians believe this ongoing irritation may contribute to symptom development in people already prone to hemorrhoids. That is a reasonable clinical observation, but it is not the same as saying diarrhea causes the underlying vein swelling.

What Actually Causes Hemorrhoids?

Straining during bowel movements is the most well-established trigger. When you strain, you increase pressure inside the abdomen and rectum. That pressure pushes against the veins in the anal canal. Over time, repeated straining weakens the tissue that holds those veins in place.

Constipation is the classic setup for this. Hard stool requires more pushing. The harder you push, the more pressure builds. This is why the standard advice for hemorrhoid prevention focuses on keeping stool soft and easy to pass — not on avoiding diarrhea.

Other factors that increase risk include:

• Pregnancy, especially in the third trimester, when the growing uterus presses on pelvic veins
• Chronic liver disease, which can raise pressure in the portal vein system
• Obesity, which increases abdominal pressure
• Prolonged sitting on the toilet, which keeps pressure on the anal veins
• Low-fiber diets, which lead to harder stool
• Heavy lifting, which raises intra-abdominal pressure

Notice what is not on that list: diarrhea. The mechanism simply does not fit the way straining does.

How Diarrhea Affects Existing Hemorrhoids

If you already have hemorrhoids, diarrhea can absolutely make them feel worse. The frequent bowel movements mean more contact between stool and already-irritated tissue. The acidic content of diarrhea can sting. The wiping required after each episode adds friction.

Some people with diarrhea also experience tenesmus — the sensation of needing to go even when the bowel is empty. That feeling can lead to repeated trips to the bathroom and repeated straining, even when there is nothing to pass. That straining, unlike the diarrhea itself, can aggravate hemorrhoids.

There is a practical takeaway here. If you have hemorrhoids and you are dealing with a bout of diarrhea, the goal is to reduce irritation, not to stop the diarrhea at all costs. Gentle cleaning, avoiding harsh wipes, and using a barrier cream can help. But the diarrhea itself is not creating new hemorrhoids.

Can Diarrhea Be a Sign of Something Else?

Yes. Diarrhea that lasts more than a few days, or that comes with blood, fever, or severe pain, needs medical attention. It can signal infection, inflammatory bowel disease, celiac disease, or other conditions that affect the digestive tract.

Blood in the stool is a particular red flag. Hemorrhoids can bleed, but so can colorectal cancer, ulcers, and inflammatory conditions. Do not assume blood is from hemorrhoids without a medical evaluation. This is not a situation for self-diagnosis.

If diarrhea alternates with constipation over weeks or months, that pattern also deserves a doctor’s attention. It can be a sign of irritable bowel syndrome, but it can also point to other conditions that need to be ruled out.

What Helps When You Have Both?

Treating diarrhea and hemorrhoids at the same time means addressing both, but not with the same approach. For the diarrhea, the priority is hydration and, if it persists, a medical evaluation. For the hemorrhoids, the priority is reducing irritation and pressure.

Practical steps that are well supported:

• Keep the area clean with water rather than harsh wipes. A bidet or a gentle rinse in the shower works well.
• Pat dry instead of rubbing.
• Use a barrier cream containing zinc oxide or petroleum jelly to protect the skin.
• Avoid sitting on the toilet longer than necessary.
• Take warm sitz baths for 10 to 15 minutes. This is a standard recommendation for symptom relief.

Over-the-counter hemorrhoid creams can help with itching and pain. They do not treat the underlying vein swelling. If symptoms last more than a week or get worse, see a doctor.

One non-obvious point: the fiber advice you hear for hemorrhoids is aimed at preventing constipation, not diarrhea. If you currently have diarrhea, adding a lot of fiber suddenly can make things worse. The goal is to get bowel movements back to a normal, formed consistency — not to push fiber aggressively during an acute episode.

When to See a Doctor

See a doctor if you have diarrhea that lasts more than two days without improvement, or if you have any of the following:

• Blood or mucus in your stool
• Severe abdominal or rectal pain
• Fever
• Signs of dehydration, such as dizziness, dry mouth, or dark urine
• Hemorrhoid symptoms that do not improve after a week of home care

These signs do not necessarily mean something serious. But they do mean the situation needs a proper evaluation rather than guesswork.