A small amount of bright red blood on the surface of the stool or found on the toilet paper is often caused by local irritation of the rectum. This could be caused by an anal fissure or hemorrhoids , which may occur after diarrhea or straining at a bowel movement because of constipation. This type of bleeding may or may occur with a painful bowel movement. This is not serious if there is only a small amount of blood and if the bleeding stops when the diarrhea or constipation stops. Home treatment usually will be all that is needed.
Bleeding can occur anywhere in the digestive tract. The blood is digested as it moves through the digestive tract. The longer it takes the blood to move through the digestive tract, the less it will look like blood, because it will be partially digested. Often blood from bleeding in the stomach will look black and tarry . Blood that has moved quickly through the digestive tract may appear red or dark red.
It is important to visit your health professional when stools are black, tarry, or mixed with blood that is bright red or dark red. Talk with your doctor any time you have new rectal bleeding or notice blood on your stools. Your health professional may recommend screening tests to rule out a more serious problem, such as inflammatory bowel disease (IBD) , colorectal cancer , or diverticulosis . There are easy tests you can get from your health professional to check for even very small amounts of blood in your stool.
Note: Some foods and medicines can also change the look of the stool. If you take bismuth subsalicylate, such as Pepto-Bismol, or iron tablets, your stool may look black, and if you eat lots of beets, your stool may turn red.
Rectal problems are often caused by constipation or diarrhea. Many prescription and nonpresciption medications can cause these conditions.
Medications that can cause either constipation or diarrhea include:
Antacids that contain aluminum or magnesium.
Antibiotics, such as ampicillin, clindamycin, tetracycline and cephalosporins.
Antidepressants and tranquilizers.
Blood pressure medications, especially clonidine or calcium channel blockers, such as verapamil.
Medications used to treat cancer (chemotherapy).
Cold medicines (antihistamines).
Diuretics, such as Lasix and HydroDIURIL.
Iron supplements or multivitamins that contain iron.
Laxatives, such as Correctol, Dulcolax, Ex-Lax, or Feen-a-Mint.
Lipid-lowering agents, such as cholestyramine.
Medications for Parkinson’s disease.
Pain medications, especially narcotics.
If you think that your rectal problem may be caused by a medication:
Call the health professional who prescribed the medication to determine whether you should stop taking the medication or take a different one. An appointment may not be necessary.
If you are taking a nonprescription medication, stop taking the medicine. Call your health professional if you feel you need to continue taking the medication.
Rectal bleeding in small amounts is common. You may see red spotting on toilet paper or drops of blood in the toilet. Rectal bleeding has many possible causes, including:
Swollen rectal veins ( hemorrhoids ), which can cause burning, pain, and bleeding. Hemorrhoids are usually caused by constipation and straining to have a bowel movement.
A tear in the lining of the rectum ( anal fissure ), which are also often caused by constipation.
Pouches that stick out of the wall of the rectum ( diverticulosis ). The pouches may bleed, or become painful and infected.
Infection, which can cause abdominal pain, fever, and bloody diarrhea.
Bleeding in the digestive tract (GI bleeding). Bleeding can occur anywhere in the digestive tract. The blood is digested as it moves through the digestive tract. The longer it takes the blood to move through the digestive tract, the less it will look like blood. Often blood that is caused by bleeding in the stomach will look black and tarry . Blood that has moved quickly through the digestive tract or that begins near the rectum may appear red or dark red.
Injury to the rectal area. Damage from anal sex or having a foreign body inserted in the rectum can cause widespread infection and severe blood loss.
Colon cancer . Rectal bleeding or spotting may be the only symptom of early colon cancer.
Rectal bleeding in children may be caused by a serious problem, such as intussusception . This occurs when the bowel twists on itself. Symptoms of rectal bleeding are present with abdominal pain and vomiting. Intussusception is a serious, life-threatening condition and requires immediate evaluation by your child’s doctor.
Treatment of rectal bleeding depends on the cause. Persistent rectal bleeding of any amount may be a sign of a serious health problem and needs to be evaluated.
Passing hard stools irritates the tissues lining the anus and may even slightly tear these tissues, causing a painful anal fissure . Rectal pain caused by constipation can trigger a vicious cycle. Pain discourages you from trying to have a bowel movement, which causes constipation to worsen, which causes more pain. The pain from passing a hard stool usually goes away within half an hour after passing the stool.
Other causes of rectal pain include hemorrhoids , an anorectal abscess or fistula , endometriosis , and cancer of the rectum or anus. When rectal pain is severe or does not improve with home treatment, a visit to a health professional is needed.
Rectal pain with a fever may be caused by an infection.
A rectal abscess is a bacterial infection with a pocket of pus in the anal area. This type of abscess may occur in a passageway that is connected to the rectum (anal fistula). Certain diseases may increase your risk for a serious infection. People who have diabetes or an impaired immune system require medical treatment at the first signs of infection.
Infection of the prostate gland (prostatitis) may cause pain that is felt in the rectum. Symptoms of a prostate infection include painful or difficult urination (dysuria) and a cloudy discharge or drip from the tip of the penis.
Sexually transmitted diseases such as genital herpes, genital warts (human papillomavirus, or HPV), chlamydia , and gonorrhea may infect the rectal area and cause pain and fever.
Rectal pain and fever also may be seen with ulcerative colitis, Crohn’s disease, ischemic bowel disease, perforation from injury, and infected hemorrhoids.
Call your health professional for an evaluation if you have rectal pain and a fever.