Ulcerative colitis is a chronic condition that develops over several stages, including mild, moderate, and severe. The stage can depend on a person’s symptoms and how much rectal bleeding they have daily.

Ulcerative colitis (UC) is a common type of inflammatory bowel disease.

UC may develop over a series of exacerbations (flares) and remissions, meaning its symptoms may worsen and improve in cycles.

The condition causes inflammation and deterioration of the colonic wall, resulting in bloody diarrhea, which may also occur with mucus. The severity of the symptoms can indicate whether a person’s condition is at a mild, moderate, or severe stage.

This article looks at the stages of UC, its symptoms, complications, treatments, and frequently asked questions.

A person walking up steps to represent the stages of a conditionShare on Pinterest
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People with ulcerative colitis typically experience diarrhea and abdominal pain. They may also have additional symptoms, such as:

  • bloody diarrhea with mucus
  • weight loss
  • fatigue
  • dehydration
  • a feeling of needing to pass stool without being able to

Some people may also show signs of a low red blood cell count (anemia) due to blood loss.

Specific symptom progression

Symptoms of UC increase in severity with each stage of the disease. Symptoms that worsen as the disease progresses can include the following:

In severe cases, UC can cause symptoms in parts of the body outside the intestines, called extraintestinal manifestations. These symptoms can include:

  • eye conditions, such as:
  • peripheral arthropathies, or joint swelling
  • erythema nodosum, a condition that causes painful bumps under the skin on a person’s shins
  • pyoderma gangrenosum, a type of skin disorder

At this point, the person may also be showing signs of hypoalbuminemia, where there is insufficient albumin protein in the blood.

Doctors may use different criteria to identify the stage of UC. However, the stage usually depends on how many bleeding episodes a person has in a day. The main stages of UC are mild, moderate, severe, and fulminant.

The classification depends on the frequency of rectal bleeding, as follows:

  • mild: fewer than four episodes per day
  • moderate: more than four episodes per day
  • severe: more than six episodes per day

A fourth category is fulminant UC, a subset of the disease that causes severe signs and symptoms with sudden onset, including:

  • more than 10 bloody stools daily
  • weight loss
  • high fever
  • abdominal tenderness

These symptoms, without treatment, may result in hospitalization.

UC complications

UC is a chronic condition that can cause complications throughout a person’s lifetime as the disease increases and decreases in severity.

Common symptoms of mild or moderate UC can contribute to malnutrition and weight loss. These symptoms include:

  • Diarrhea: This can cause dehydration, which means the body is low in fluids, nutrients, and necessary electrolytes, such as:
  • Abdominal pain and nausea: These symptoms can reduce a person’s appetite, making it difficult for someone to consume enough calories and sufficient nutrients.
  • Rectal bleeding: This bleeding can lead to iron deficiency anemia.
  • Frequent bowel movements: This may cause a person to eat less to avoid diarrhea, putting a person at risk of becoming malnourished.

More severe complications that can occur throughout the stages of UC, but particularly at later stages, include:

While there is no cure for UC, there are treatments available.

Some treatments span multiple stages of UC, including:

  • oral aminosalicylates, such as mesalamine or sulfasalazine
  • topical aminosalicylates
  • corticosteroids
  • immunomodulators
  • biologics
  • targeted synthetic small molecules

Learn more about UC-approved drugs.

The following table shows treatments for UC according to the specific stage.

mild• oral aminosalicylates, or 5-ASA
enema with 5-ASA
moderate• oral 5-ASA
• enema with 5-ASA
• oral glucocorticoids
• enema with glucocorticoids
• immunomodulators
• targeted synthetic small molecules
• biologics
severe• oral or IV glucocorticoids
• enema with glucocorticoids
• immunomodulators
• targeted synthetic small molecules
• biologics
fulminant• IV glucocorticoids
• IV cyclosporine
• immunomodulators
• targeted synthetic small molecules

Below are some frequently asked questions about UC.

How fast does UC progress?

UC usually develops gradually. However, the onset can also be very rapid, particularly in the case of fulminant UC.

How long do symptoms of UC typically last?

The duration of UC flares varies from days to months.

How do doctors determine the stage or severity of UC?

Doctors grade the severity of UC according to rectal bleeding. Factors that determine the stage can vary slightly according to different criteria.

What is the most common age to receive a diagnosis of UC?

There are two peak ages when UC may develop. The most common age for someone to receive a diagnosis is between 15 and 30 years, but the risk increases again between 50 and 70 years of age.

How do flares of UC vary between mild, moderate, and severe cases?

UC symptom flares typically worsen with each stage, with severe cases causing the most significant symptoms and complications.

UC is a chronic type of inflammatory bowel disease that may have periods of flares and remissions. The main indications of UC are bloody diarrhea and abdominal pain.

The stage of UC typically depends on how many bleeding episodes a person has in a day.

The main stages of UC are mild, moderate, severe, and fulminant. Fulminant UC is a subset of the condition that causes sudden and severe symptoms.

UC is not curable with medication, but treatments can reduce the frequency and severity of flares specific to the stage.