Blood on toilet paper: 6 possible causes and what to do

The color and appearance of the blood give a clue about where the bleeding is coming from, but they are not enough to make a diagnosis:

• Bright red blood appears on the paper, on the stool or as drops in the toilet bowl. Bleeding from the anal canal and rectum often looks like this: hemorrhoids, an anal fissure. But rectal cancer can also cause bright red bleeding.
• Dark red blood, clots or blood mixed into the stool may indicate that the bleeding is higher up in the bowel.
• Black, sticky, tar-like stool is often a sign of bleeding from the stomach or duodenum and needs urgent care. Iron supplements can also turn stool black, and beets can give it a reddish color, but a doctor should be the one to tell the difference.
• Bloody mucus can be a sign of inflammation or a polyp in the bowel.
• Blood-and-pus stains on underwear often point to inflammation around the anus, such as a fistula.

The amount of blood can also be misleading: cancer may bleed only a little, while hemorrhoids can bleed enough to turn the toilet water red. Sometimes blood can't be seen at all and is found only with a fecal occult blood test.

1. Hemorrhoids (piles)

This is the most common cause. Bleeding from hemorrhoids is usually bright red, appears on the paper or as drops in the toilet bowl after a bowel movement, and is often painless. There may also be itching, burning and a lump that comes out during bowel movements. If a clot forms in a hemorrhoid (thrombosis), sudden and severe pain begins. Bleeding that recurs over a long time can cause anemia. More: what are hemorrhoids and hemorrhoid treatment.

2. Anal fissure

An anal fissure (fissura, often simply called a “tear”) is a long, narrow wound in the skin of the anal canal. Its main symptom is a cutting, burning pain during and after a bowel movement. The pain sometimes lasts for hours. There is little blood, and it appears as a streak on the paper. An acute (fresh) fissure often heals within a few weeks, while a fissure lasting more than 6–8 weeks is considered chronic. Fear of pain makes people put off going to the toilet, which leads to constipation and a deeper fissure. More: anal fissure treatment.

3. Anal abscess (paraproctitis) and anal fistula

An anal abscess (paraproctitis) is a pus-filled inflammation around the anus: it comes with throbbing pain, swelling, redness and often fever. After the abscess opens, a thin channel between the anal canal and the skin, called an anal fistula, may remain. With a fistula, there are blood-and-pus stains on underwear, and a small opening can be seen near the anus. An abscess cannot be “covered up” with antibiotics: it has to be opened surgically. More: anal abscess and anal fistula.

4. Colon polyps

A polyp is a growth on the lining of the colon or rectum. It often causes no symptoms, but as it grows there may be blood, mucus, constipation or diarrhea. Some polyps can turn into cancer over the years, so they should be removed in time. Polyps are more common in people whose relatives have had polyps or bowel cancer. A polyp found during a colonoscopy can often be removed during the same procedure and sent for testing. More: colon polyps.

5. Inflammatory bowel disease and proctitis

Ulcerative colitis and Crohn's disease are chronic inflammation of the bowel wall. The blood often comes with mucus and diarrhea, and you may need to get up at night to use the toilet. There may be abdominal pain, weight loss, fatigue and fever. These diseases often start at a young age and need long-term treatment. Inflammation of the rectum (proctitis) shows up as a frequent urge to go that produces little or nothing, along with mucus and blood. Irritable bowel syndrome does not cause bleeding: if there is blood, another cause must be looked for.

6. Colon, rectal and anal cancer

Bowel cancer can develop without symptoms for a long time. Warning signs include blood or mucus in the stool, a change in bowel habits lasting weeks, thinner stools, a feeling that the bowel hasn't emptied completely, unexplained weight loss, weakness and anemia. The symptoms of anal cancer (blood, a lump, pain, itching) can closely resemble hemorrhoids.

The risk increases with age. Bowel cancer or polyps in the family, inflammatory bowel disease, smoking, alcohol, excess weight, and eating a lot of red and processed meat also raise the risk. Cancer found at an early stage has a much better chance of successful treatment.

This table is only a rough guide. One person can have several causes at once, for example, both hemorrhoids and a polyp.

Any time you see blood on toilet paper, you need a scheduled examination. Especially don't delay if:

• the bleeding has happened more than once;
• you are over 40;
• your bowel habits have changed or your stools have become thinner;
• you have weakness, paleness or unexplained weight loss;
• you have persistent abdominal pain, cramps or bloating;
• there is a family history of bowel cancer or polyps.

Emergency signs: don't wait

Call an ambulance (103) or go to the emergency department of the nearest hospital if:

• the bleeding is heavy, won't stop, contains clots or turns the toilet water red;
• along with the bleeding, you have dizziness, fainting, a racing heart, cold sweats or sudden paleness;
• your stool is black and tar-like;
• you have severe abdominal pain or a fever along with the bleeding;
• you have swelling and throbbing pain around the anus with a fever;
• you take blood thinners and the bleeding is increasing.

Having hemorrhoids does not mean there is no other cause of the bleeding. A person can have hemorrhoids and a polyp or tumor at the same time. Suppositories and ointments from the pharmacy can temporarily reduce the bleeding and create a false sense of security, while the disease quietly progresses.

The reasons for delay are usually the same: embarrassment, fear of the examination, and advice from friends such as “there's no point seeing a doctor until the bleeding gets worse.” Yet when a disease is found before it becomes serious, treatment is simpler. The examination is confidential, and both the doctor and the team are women.

A patient's story

One of our patients had put off seeing a doctor for months, believing the ongoing bleeding was due to hemorrhoids, and finally came to us for hemorrhoid surgery. The examination revealed that the bleeding was caused by a cancer that completely blocked the lumen (the inner channel) of the bowel. Treatment became much more complicated and required major surgery. Had the patient come in at the first sign of bleeding, the situation might have been different. Every patient's situation is individual.

To find the cause of the bleeding, these steps are usually taken:

1. Conversation. The doctor asks about the color and amount of the blood, how long it has been happening, pain, bowel habits and bowel diseases in your family.
2. Visual and digital rectal examination. This takes a few minutes and is done in private.
3. Anoscopy. The anal canal is examined with a small, lubricated tube. Hemorrhoids and anal fissures are often visible at this stage.
4. Rectoscopy. If there is bleeding, the rectum is examined.
5. Colonoscopy. The entire colon is examined. If a polyp is found, it is often removed during the same procedure.

We recommend a colonoscopy for patients over 40 who have constipation and hemorrhoids, as well as for anyone with worrying signs (weight loss, anemia, thin stools, bowel cancer in the family). Even without any symptoms, bowel cancer screening is recommended from age 45–50. If the disease runs in your family, you may need to start earlier. A colonoscopy is often done under light sedation. On preparation and what to expect: colonoscopy. We explain how a first proctology visit goes in our article what is a proctologist.

Do:

• note the color and amount of the blood and when it appears; this helps the doctor;
• drink about 1.5–2 liters of water a day (unless your doctor has told you otherwise) and eat high-fiber foods;
• don't sit on the toilet for more than 5 minutes and don't strain.

Don't:

• use suppositories, ointments or medication to stop bleeding without a doctor's prescription;
• stop taking blood thinners on your own; talk to your doctor first;
• put off the examination, telling yourself “it happened once, and it's gone.”