Ulcerative colitis is a long-term inflammatory bowel disease that can affect the texture, composition, and frequency of stools.

In people with ulcerative colitis (UC), the large intestine, or colon, becomes inflamed and develops small, pus-producing ulcers. These ulcers can also develop in the rectum.

The type of stool symptoms people experience will depend on the location of inflammation and ulceration within the colon.

This article outlines the various stool symptoms of UC, along with the possible treatment options


Doctors may use a Bristol Stool Chart to help a person recognize healthy bowel movements or identify possible problems.

The stool changes that occur in UC are due to inflammation. Over time, inflammation can damage the lining of the large intestine.

Bristol stool chartImage credit: Kylet, 2011

Stool symptoms

People with UC may experience painful abdominal cramps and a frequent need to empty the bowels.

According to the Crohn’s and Colitis Foundation (CFF), a person with UC may also experience the following symptoms:

  • diarrhea
  • stools containing mucus or blood
  • pain in the abdomen

According to another organization, 75 percent of people with an inflammatory bowel disease (IBD) have also experienced bowel incontinence — the unintended passing of stools, or “having an accident.”

Also, some people with IBD experience constipation instead of diarrhea.

Learn more about the common stool changes below:


Diarrhea occurs when intestinal damage becomes so extensive that the colon loses its ability to absorb water from waste.

When waste retains too much water, it results in loose stools.

Blood in stools

Often, the ulcers that form within the lining of the colon can bleed, resulting in bloody stools.

A person who regularly loses a lot of blood in their stools may develop anemia.


mature lady with stomach ache sitting on sofa
Ulcerative colitis may cause severe stomach cramps.

Although the majority of people with UC will have loose stools, some may also experience constipation.

However, constipation is more common among people with proctitis, in which inflammation and ulceration affect only the rectum.

Symptoms of constipation include:

  • reduced frequency of bowel movements
  • harder stools
  • difficulty passing stools
  • bloating
  • cramping
  • feeling that the bowels are not empty even after a bowel movement

Bowel incontinence

Most people with UC tend to experience bowel incontinence during a flare-up of the disease.

However, around 1 in 10 people with IBD who experience bowel incontinence will do so during a period of disease remission.

The following factors may cause bowel incontinence:

Increased sensitivity of the rectum

As the rectum becomes inflamed, it will also become more sensitive. Heightened sensitivity in the rectum can cause it to become more active, pushing out stools as soon as they arrive.

IBD surgery

People with severe UC may have surgery to remove all or part of the large intestine.

In “pouch surgery,” the surgeon replaces the colon with an internal pouch. Some people who undergo this procedure may develop bowel incontinence.

Severe constipation

A buildup of stools can irritate the lining of the rectum, causing an overproduction of mucus.

If the rectum constantly contains stools, the muscles of the anus relax, allowing the mucus to leak out.

How to reduce stool symptoms

The following treatments for UC reduce inflammation that leads to stool symptoms:

  • Aminosalicylates, which are drugs that target inflammation in the lining of the colon.
  • Corticosteroids, which are powerful, fast-acting anti-inflammatories used to treat UC flare-ups.
  • Immunomodulators, which are drugs that regulate the immune system.
  • Biologics, which target inflammation in the gut.

Treating diarrhea

People with IBD should avoid taking antidiarrheal medications.

Antidiarrheal drugs can increase the risk of a complication called megacolon, in which digestive gases become trapped in the colon, causing it to swell. In some cases, this can be fatal.

The safest way to treat diarrhea is to make dietary changes. Many people with UC experience diarrhea after eating specific foods.

Keeping a food diary along with a daily record of stool symptoms can help people identify and eliminate these trigger foods.

Reducing blood in stools

A recent study suggests that a prebiotic supplement may help reduce bloody stools and other symptoms of UC.

Participants taking the prebiotics supplement experienced significantly decreased abdominal pain and cramping. They also reported reduced nausea, vomiting, diarrhea, and blood in stools, although these effects were not statistically significant.

The study was small, so more research is needed to determine the best way to reduce blood in stools.

If a person frequently has bloody stools, a doctor may prescribe iron supplements to help prevent anemia.

Treating constipation

woman keeping a food diary
Keeping a food diary can help identify the cause of the symptoms.

The International Foundation for Gastrointestinal Disorders (IFFGG) recommend the following treatments for mild constipation:

  • drinking plenty of fluids
  • eating fibrous foods, such as uncooked fruits and vegetables
  • eating whole-grain bread and cereals

However, many people with UC find that fibrous foods and whole grains trigger other symptoms, so keeping a food diary can help people identify which foods cause which symptoms.

Other methods for relieving constipation include:

  • Squatting while having a bowel movement: Sitting with the knees higher than the hips when using the toilet can help align the rectum, making stools easier to pass.
  • Exercising: Exercise helps speed up the movement of stools through the colon.
  • Taking laxatives: Doctors may recommend osmotic laxatives for people with IBD. These increase water availability in the colon, which helps to soften stools.

However, people with UC should talk to a doctor before taking laxatives, as these medications can increase wind and stomach cramps.

Managing bowel incontinence

Many people who experience bowel incontinence find it difficult to discuss the issue with a doctor.

However, a doctor may be able to identify the underlying cause of a leaky bowel and can offer advice on how to control and manage this symptom.

Some suggestions for managing bowel incontinence include:

Bowel retraining

People who experience a sense of urgency may benefit from delaying bowel movements. This technique is called bowel retraining.

Although bowel retraining may be difficult at first. Over time, however, it will help build up strength and control over the rectum and sphincter muscles.

Pelvic floor exercises

The pelvic floor muscles support the pelvic organs, which include the bladder and bowel, as well as the uterus in women.

Pelvic floor exercises can help strengthen the muscles around the anus, reducing incontinence. To find the pelvic floor muscles, imagine stopping a urine stream or practice while urinating.

To perform pelvic floor exercises, contract and hold the pelvic floor muscles for a count of 3, and then relax the muscles, while slowly counting to 3. Avoid pushing out the muscle during the relaxation stage.

Repeat this 15 times to complete one set of exercises. Aim to complete three sets each day.


People with UC may experience uncomfortable, inconvenient, and sometimes distressing stool symptoms. These can greatly affect a person’s quality of life.

However, there is a range of treatments that can help those with UC to experience fewer and less severe symptoms.

A person should discuss the options with their doctor to establish the most effective treatment plan.