Constipation and blood in the stool can occur at the same time, due to many different reasons. For most people, blood in stool may occur due to issues with bowel movements, tears to the anus, or hemorrhoids.
Constipation refers to infrequent and uncomfortable bowel movements. A person has constipation when they pass small amounts of hard, dry stool less than
People may have constipation for many reasons. Sometimes, there is no apparent reason. It commonly happens when stool moves too slowly through the digestive tract due to less water consumption, dietary changes, or decreased activity. The slower stool movement increases water absorption from the stool, making it hard and dry and more difficult to eliminate from the rectum.
Chronic constipation has several potential causes and can lead to various complications that may result in bleeding.
This article examines whether constipation can lead to blood in stools. We discuss the associated symptoms of rectal bleeding from constipation and how to treat it. We also look at some frequently asked questions on the subject.
Although it is not common and does not occur in everyone, people may experience blood in their stool with constipation for the following reasons:
An anal fissure is a tear or ulcer that develops in the tissue that lines the anus. Anal fissures are
Anal fissures tend to cause sharp rectal pain with bowel movements and some rectal bleeding. They can be acute and last for
Hemorrhoids are swollen and inflamed blood vessels that can develop externally under the skin around the anus or internally in the lining of the anus or lower rectum. Hemorrhoids are common, affecting around
- straining during bowel movements
- passing hard stools
- having chronic constipation
Due to their rich vascular supply, hemorrhoids often bleed, causing bright red blood to coat the stool, drip into the toilet, or be visible on toilet tissue. Hemorrhoids are the
Fecal impaction occurs when stool becomes hard and dry and gets stuck in the colon. An impacted colon blocks the way for waste to leave the body and instead makes it way back inside the large intestine, causing
Most people with fecal impaction have chronic constipation. Rectal bleeding is a common symptom of fecal impaction.
Several other conditions are associated with constipation and may cause blood in bowel movements. These include the following:
- Rectal prolapse: This occurs when the lowest part of the large intestine slides out through the anus, producing a lump. People with rectal prolapse
may experienceconstipation and pass blood from the rectum.
- Colon cancer: This cancer usually begins as noncancerous clumps of cells called polyps inside the colon. Over time, some polyps can become cancerous. Colon cancer
may causepersistent changes in bowel habits, rectal bleeding, and blood in the stool.
- Diverticular diseases: Diverticular diseases occur when multiple small pouches — diverticula — develop and push outward through weak areas in the colon wall, leading to inflammation in some people. Blood vessels in the wall of the pouches
can becomebrittle with time, making them rupture and bleed. Diverticular disease can also lead toconstipation.
- Abdominal cancer: Abdominal tumors can narrow the bowel and rectum, making it difficult for someone to have a bowel movement and causing constipation. These tumors may also
causeblood in stool.
- Rectal cancer: This begins in the rectum and
may causebowel changes, such as constipation and blood in stool.
- Chronic inflammatory conditions: This can include inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis, among others.
Symptoms can vary according to the cause of constipation and rectal bleeding. Aside from the symptoms listed above, others may include:
- hemorrhoid pushing through the anus, causing irritation and pain
- a tear in the skin around the anus
- hard, tender lumps near the anus
- a small skin tag or lump on the skin near the anus
- abdominal pain or bloating
- difficulty passing gas
- swelling around the anus
- anal itching
- anal pain when sitting
- leaking liquid stool
- losing appetite
- unexplained weight loss
If people are concerned about their symptoms, they should contact a healthcare professional as soon as possible to rule out severe conditions.
If anal fissures, hemorrhoids, or other conditions are causing constipation and bleeding, a doctor will treat the specific cause of the symptoms. Overall, treatments aim to:
- improve bowel movements
- stop bleeding
- relieve any associated symptoms
A doctor may recommend the following strategies for constipation:
28–34 gramsof fiber daily to keep stool soft and improve fissure healing.
- Drinking enough fluids to prevent constipation.
- Avoiding straining during bowel movements because the pressure can cause new tears or open a healing tear.
- Taking fiber supplements such as methylcellulose (Citrucel) or psyllium (Metamucil).
- Trying stool softeners, such as docusate (Colace).
- Using stimulant laxatives, such as bisacodyl (Dulcolax).
- Trying prescription medications, such as lubiprostone (Amitiza), linaclotide (Linzess), or prucalopride (Motegrity).
- Getting regular physical activity.
- Trying bowel training. For example, aim to have a bowel movement
15–45 minutesafter breakfast, as eating helps move stool.
Below are some common questions and answers on the topic:
How do doctors evaluate blood in stool?
A doctor will first take a
Is bright red blood in stool serious?
A small amount of red blood from the anus that happens once or twice is not usually a sign of something serious and could result from constipation. This one-off bleeding will often resolve without treatment.
However, if bleeding lasts over a couple of days or is heavy and in multiple bowel movements, a person should consult a doctor. Some causes of rectal bleeding are serious and need urgent treatment.
When should I worry about blood in stool?
People should seek emergency help if they have the following symptoms of shock with rectal bleeding:
- rapid, shallow breathing
- pale, cold, clammy skin
- weakness and dizziness
- blurred vision
- unable to urinate
A person should attend the emergency room immediately if they have continuous or heavy rectal bleeding or rectal bleeding with severe abdominal pain and cramping.
People may experience constipation and blood in stool for many reasons, ranging from mild to severe. For most people, bleeding may occur due to issues with bowel movements, tears to the anus, or hemorrhoids, and it can improve with home treatments.
Some causes of constipation and rectal bleeding are severe and require prescription treatments and, in some cases, surgery. Severe causes of constipation and bleeding may include conditions such as colon and rectal cancer.
A doctor should check rectal bleeding lasting more than a few days. If people have symptoms of shock with rectal bleeding, they should get immediate medical advice. They should go to the emergency room if bleeding is heavy, continuous, and with severe abdominal symptoms.