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Whether you call it flatulence, breaking wind, or passing gas, farting is completely normal. Most people pass gas anywhere from 5 to 15 times a day.

But it isn’t normal for blood to appear when you pass gas.

If you have watery stools, passing gas can cause a wet fart. This is when a little liquid or mucus passes with the gas. Sometimes, a little blood can mix with this liquid, resulting in traces of blood in your underwear.

Even though passing gas can sometimes indicate a serious health problem, some reasons for blood appearing when you pass gas aren’t serious.

Here’s a look at 11 reasons why blood may appear when you fart, and when to be concerned.

Chafing is a rash-like skin condition caused by friction when skin repeatedly rubs together. Chafing can affect the breasts, inner thighs, armpits, and the skin between the butt cheeks.

Skin that’s irritated from chafing can become inflamed, resulting in itchiness, redness, burning, and sometimes bleeding. When you pass gas, blood may come out of the chafed area and into your underwear.

This isn’t serious and can be treated at home. Learn about five home remedies that can help soothe chafed skin.

Blood can also appear when you pass gas if you have hemorrhoids. These are inflamed, swollen veins on the inside or outside of the anus.

Some hemorrhoids don’t cause symptoms, but they can bleed. You might see bright streaks of red blood when wiping after a bowel movement. Similarly, if a watery stool causes you to pass gas, blood from a hemorrhoid can mix with this liquid and result in the appearance of blood.

Hemorrhoids can happen after long periods of straining to have a bowel movement. Over-the-counter treatments, such as suppositories, can reduce swelling and help a hemorrhoid heal.

Occasionally, straining to have a bowel movement may cause anal fissures. These are small tears in the thin skin that lines the anus.

Anal fissures can be painful and bleed during or after a bowel movement. Sometimes, bleeding may happen after passing gas.

Like hemorrhoids, anal fissures are temporary. They usually heal on their own within a few weeks.

Anal fissures can be treated at home with sitz baths and by applying topical hydrocortisone creams or topical pain relievers, such as lidocaine, to reduce inflammation and discomfort.

Some medications cause bleeding as a side effect. This can cause blood to appear when you pass gas. Medications that can cause GI bleeding include:

If you see blood, check your medication to see if GI bleeding is a side effect and notify your doctor as soon as possible.

A colonoscopy can reveal colon polyps on the lining of your colon. These are clumps of harmless, small cells. Blood can appear after you’ve passed gas when colon polyps are bleeding.

Although typically benign, colon polyps can increase your risk for colon cancer. See your doctor if you believe you may have colon polyps or have any of these other symptoms:

Diverticulitis is inflammation of bulging pouches (diverticula) that form in the intestines.

You may not have any symptoms with diverticulitis. But this condition can cause stomach cramps, bloating, constipation, and sometimes GI bleeding. GI bleeding can sometimes cause blood to appear after you pass gas.

Diverticulitis is treatable with antibiotics and pain relievers. In severe cases, surgery may be necessary to remove the diseased part of the intestines.

See your doctor as soon as possible if you have any symptoms of diverticulitis, including:

Gastritis is stomach inflammation that affects the lining of the stomach and can also cause bleeding in the GI tract. Symptoms can include blood in your vomit and poop.

Taking antibiotics and antacids can help reduce stomach acid and ease symptoms.

But you should see your doctor if you believe you have gastritis, especially if you’ve had symptoms like abdominal pain, nausea, and vomiting that haven’t gotten any better over a few days or weeks.

Blood appearing when you pass gas can also indicate injury to the GI tract from trauma to the body, such as from a car accident, bike accident, or fall.

Depending on the severity, you may need surgery to help treat injuries. With severe injuries, intestinal fluids can leak into the stomach, causing a life threatening emergency.

If blood suddenly appears when you pass gas immediately or a short time after an injury, get immediate or emergency medical care.

Ulcerative colitis (UC) is a chronic, inflammatory bowel disease. This condition causes inflammation in the digestive tract, resulting in symptoms like:

  • rectal bleeding
  • stomach pain
  • bloody diarrhea

UC increases your risk for colon cancer. If left untreated, the condition can cause:

  • holes in your colon
  • severe dehydration
  • blood clots

UC can be treated with anti-inflammatory drugs and immunosuppressant drugs. These help stop inflammation and suppress the immune system, which helps the colon heal.

Antidiarrheal medications and pain relievers can also help improve symptoms.

Never ignore blood that appears after you pass gas, as it could be a sign of colon cancer.

This is a type of cancer that develops in the large intestines. Symptoms can include:

  • change in bowel habits
  • change in stool consistency
  • severe or persistent stomach pain
  • bloody stools

See your doctor as soon as possible if you notice any of the symptoms above, especially if they’ve lasted for a few days and aren’t getting any better.

Crohn’s disease is another form of inflammatory bowel disease (IBD) that can cause blood to appear when you pass gas or have a bowel movement.

Some common symptoms that you might experience along with bleeding include:

See your doctor if you have any of the symptoms above for extended periods of time and they aren’t getting any better.

Here are pictures of some conditions that may cause bleeding after passing gas.

Blood appearing when you pass gas is often accompanied by other symptoms. Tracking your symptoms can help you determine an underlying cause.

Other symptoms can be mild or severe, depending on the cause. For example, if you have chafing in your buttocks, hemorrhoids, or anal fissures, you may have anal pain and itching, too.

If medications are the cause, bleeding might only affect the intestinal tract but may be accompanied by symptoms like:

  • fatigue
  • loss of appetite
  • headache

Seek medical attention as soon as possible if you notice any of the following symptoms:

  • severe abdominal pain
  • bloody stools
  • change in bowel habits or stool consistency

See a doctor for bloody stools

Seeing blood after you pass gas doesn’t usually require a doctor’s visit, especially if you have symptoms of less serious problems like hemorrhoids or anal fissures.

You should, however, see a doctor for bloody stools. Keep in mind that bloody stools don’t always appear red. Sometimes, these stools are black in appearance.

A colonoscopy or endoscopy can examine the GI tract and help diagnose underlying causes.

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You can’t prevent all of these causes. But if you have a history of hemorrhoids or anal fissures, try the following to help prevent or reduce symptoms:

  • drink plenty of fluids
  • get regular physical activity
  • avoid straining during bowel activity

You can ask your doctor about alternative medications if you believe you’re experiencing drug-induced bleeding.

If you’ve been diagnosed with a chronic gastrointestinal condition:

  • take medication as directed
  • consider making dietary changes, such as eating more fiber, to help soften stools and stop GI inflammation

How to prevent excess farting

Here are some tips if you also want to try to limit how often you pass gas:

  • Reduce foods that you notice result in excess farting, keeping a food journal of foods that cause you to fart more.
  • Eat smaller meals more often throughout the day to limit stress on your GI tract.
  • Eat slower so that you swallow less air that can cause you to fart.
  • Get regular exercise to limit gas build-up — shoot for about 30 minutes of moderate exercise per day.
  • Reduce the fat content of your foods, as fat can slow down your digestion.
  • Use over-the-counter treatments for excess gas, such as simethicone (Gas-X, Mylanta Gas) to reduce gas bubbles or Beano to reduce gas that happens during digestion of foods with high amounts of fiber.
  • Reduce or quit smoking or gum chewing, which can both cause you to swallow excess air.
  • Reduce or avoid soda, beer, and carbonated drinks that cause gas bubbles in your GI tract.

Blood appearing after you pass gas isn’t always a cause for concern and you can often treat it at home.

See your doctor if you’re concerned about blood after you pass gas or notice any severe symptoms like pain, discomfort, blood in your stools, or difficulty having a bowel movement.