Ulcerative Colitis: Symptoms, Diagnosis, Treatment, and What to Expect

Ulcerative colitis can feel confusing and worrying, especially when symptoms such as bloody diarrhea or urgent trips to the bathroom begin to affect daily life. The good news is that ulcerative colitis is a well-recognized condition, and many people are able to manage it well with the right care.

This guide explains ulcerative colitis in clear, simple language: what it is, why it happens, how doctors diagnose it, how it is treated, and what complications to watch for.

What Is Ulcerative Colitis?

Ulcerative colitis is a long-term inflammatory bowel disease, often called IBD.

It affects the colon, which is the large intestine. The inflammation usually starts in the rectum, the last part of the bowel, and may spread upward through part or all of the colon.

In ulcerative colitis, the inflammation affects the inner lining of the colon. This can lead to irritation, ulcers, bleeding, and changes in bowel habits.

A key feature is that the inflammation is usually continuous. That means it spreads in one connected area rather than appearing in scattered patches.

How Common Is Ulcerative Colitis?

In the United States, about 1.2 million adults are affected by ulcerative colitis.

It can happen at any age, but it most often begins between 20 and 30 years old. A smaller increase is also seen in people over 55 years old. More than 10% of patients develop symptoms during childhood.

Ulcerative colitis affects men and women about equally.

It is more common in White populations and is highest among people of Ashkenazi Jewish descent.

What Causes Ulcerative Colitis?

The exact cause is not fully known.

Current understanding suggests that ulcerative colitis happens when the immune system reacts abnormally inside the bowel. In simple terms, the body’s defense system becomes overactive and causes ongoing inflammation in the lining of the colon.

Several factors may increase the chance of developing ulcerative colitis, including:

• Family history of inflammatory bowel disease

• Genetic tendency

• Certain ethnic backgrounds

• Previous intestinal infections

• Higher intake of fat, especially saturated fat and animal fat

• Oral contraceptive use

• Use of NSAIDs, which may worsen ulcerative colitis in some people

NSAIDs are common pain-relieving medicines such as ibuprofen or naproxen.

Some factors have been linked with a lower risk, including appendectomy and smoking. However, smoking is harmful to overall health and should not be used as a way to prevent or treat ulcerative colitis.

Main Symptoms of Ulcerative Colitis

The most common symptom is bloody diarrhea.

Other bowel symptoms may include:

• Mucus in the stool

• Needing to use the bathroom urgently

• Going to the bathroom more often than usual

• Abdominal pain or cramping

• A constant feeling that you need to pass stool, even when little or nothing comes out

  
  

That last symptom is called tenesmus.

Symptoms can come and go. Many people have flare-ups followed by periods of improvement or remission. Others may have more continuous symptoms.

Symptoms Outside the Gut

Ulcerative colitis can affect more than the bowel. These are called extraintestinal manifestations, meaning symptoms outside the intestine.

They may include:

• Fatigue

• Fever

• Joint problems such as arthritis

• Eye inflammation

• Skin problems

• Mouth sores

• Liver and bile duct problems, including a condition called primary sclerosing cholangitis

Joint symptoms are the most common symptoms outside the bowel.

Primary sclerosing cholangitis, often shortened to PSC, is uncommon in people with ulcerative colitis, but it is strongly linked with inflammatory bowel disease when it does occur.

Types of Ulcerative Colitis by Location

Doctors often describe ulcerative colitis based on how much of the colon is affected.

Ulcerative proctitis

This is limited to the rectum.

Left-sided ulcerative colitis

This affects the rectum and the left side of the colon.

Extensive ulcerative colitis

This extends farther into the colon, beyond the left side. It may involve much of the colon.

Knowing the extent of disease helps doctors choose the most suitable treatment and monitoring plan.

How Severe Can Ulcerative Colitis Be?

Ulcerative colitis can be mild, moderate, severe, or fulminant.

In mild disease, a person may have fewer than four stools per day and only occasional blood.

In more severe disease, symptoms may include:

• More frequent stools

• Frequent or continuous blood in the stool

• Strong urgency

• Anemia

• Raised inflammation markers in blood tests

• More severe inflammation seen during colonoscopy

Acute severe ulcerative colitis can come on suddenly and may cause severe diarrhea, dehydration, and even shock. This needs urgent medical care.

How Is Ulcerative Colitis Diagnosed?

Doctors diagnose ulcerative colitis using a combination of symptoms, stool tests, blood tests, colonoscopy, and biopsy.

Stool tests

Stool testing is important to rule out infections that can look similar to ulcerative colitis. Doctors may test for infections such as Clostridioides difficile.

A stool marker called fecal calprotectin may help show how active the inflammation is and whether treatment is working.

Blood tests

Blood tests do not diagnose ulcerative colitis by themselves, but they help doctors understand how active or severe the disease may be.

They may show:

• Anemia

• Raised white blood cells

• Raised platelets

• High ESR or CRP, which are signs of inflammation

• Low albumin

• Liver test changes if PSC is present

Colonoscopy with biopsy

The main test used to confirm ulcerative colitis is an ileocolonoscopy with biopsy.

This means a doctor looks inside the colon and the end of the small intestine using a flexible camera. Small tissue samples are taken and checked under a microscope.

In severe disease, colonoscopy must be done carefully because there is a higher risk of bowel injury.

What Doctors May See During Colonoscopy

In early ulcerative colitis, the lining of the colon may look red, swollen, and easily irritated. It may bleed when touched.

Doctors may also see small ulcers.

In long-term disease, changes may include:

• Loss of normal blood vessel pattern

• Loss of folds in the colon lining

• Pseudopolyps, which are raised areas caused by repeated healing and inflammation

• Narrowing or strictures

• Deeper ulcers in advanced disease

Pseudopolyps can look like polyps, but they develop from inflammation and healing rather than from cancerous change.

Other Tests and Imaging

Imaging is not usually needed to make the diagnosis, but it can help in certain situations.

Doctors may use abdominal X-rays, CT scans, MRI scans, or ultrasound when:

• Complications are suspected

• Colonoscopy is not possible

• Symptoms are not fully explained by endoscopy

• Doctors need to check how much of the bowel is affected

• Doctors need to distinguish ulcerative colitis from other conditions

In severe disease, an abdominal X-ray may help check for toxic megacolon or perforation.

Conditions That Can Look Like Ulcerative Colitis

Several conditions can cause similar symptoms, especially diarrhea, bleeding, or abdominal pain.

Doctors may consider:

• Crohn disease

• Infectious colitis

• C. difficile colitis

• Ischemic colitis

• Diverticular disease

• Microscopic colitis

• Radiation colitis

• Celiac disease

• Appendicitis

• Certain bacterial, viral, or parasitic infections

This is why stool testing, colonoscopy, and biopsy are so important.

How Is Ulcerative Colitis Treated?

Treatment depends on how severe the disease is and how much of the colon is affected.

The main goals are to:

• Calm the inflammation

• Relieve symptoms

• Help the bowel lining heal

• Keep the disease in remission

• Prevent complications

A gastroenterologist usually guides treatment.

Supportive Care

Supportive care is important for all patients.

This may include:

• Managing pain safely

• Using non-medicine approaches such as heating pads

• Considering acetaminophen when appropriate

• Avoiding NSAIDs if they worsen symptoms

• Avoiding opioids when possible

• Checking for and treating malnutrition

Nutrition support may be needed if a person is not eating well or has poor nutritional status.

Medicines for Ulcerative Colitis

5-ASA medicines

For mild to moderate ulcerative colitis, 5-ASA medicines are often first-line treatment.

One common example is mesalamine.

These medicines may be taken by mouth, used rectally, or both, depending on where the inflammation is located.

For ulcerative proctitis, rectal treatment such as a suppository or enema may be used. For left-sided or extensive colitis, oral medicine plus rectal treatment may be recommended.

Steroids

Glucocorticoids, often called steroids, may be used to bring a flare under control when 5-ASA treatment is not enough.

Examples include prednisone, budesonide, methylprednisolone, or hydrocortisone.

Steroids are usually used to induce remission, meaning to calm an active flare. They are not preferred as long-term maintenance treatment.

Immune-targeting medicines

For moderate to severe disease, doctors may consider medicines that act on the immune system.

These may include anti-TNF medicines such as infliximab, adalimumab, or golimumab. Some patients may also receive medicines such as azathioprine.

The exact choice depends on disease severity, previous treatment response, and individual risk factors.

Acute severe ulcerative colitis

Acute severe ulcerative colitis may require hospital treatment with IV steroids. If symptoms do not improve quickly, other medicines such as cyclosporine or infliximab may be considered.

Surgery for Ulcerative Colitis

Surgery can be curative for ulcerative colitis because the disease affects the colon and rectum.

Surgery may be considered when:

• Medicines do not work

• Severe disease does not improve after several days of treatment

• Steroid dependence develops

• Toxic megacolon occurs

• Bowel perforation occurs

• Severe bleeding occurs

• Dysplasia or cancer is found

A common surgical option is restorative proctocolectomy with ileal pouch-anal anastomosis, often called a J pouch.

In this operation, the colon and rectal lining are removed while preserving the anal sphincters. A pouch is made from the small intestine to act like a new rectum, allowing stool to pass through the anus.

Possible complications include leakage, infection, bowel narrowing, bowel blockage, fertility issues, sexual dysfunction, and pouchitis. Pouchitis is inflammation of the pouch and may cause increased stool frequency, tiredness, and sometimes leakage.

Possible Complications

Most people with ulcerative colitis do not develop every complication, but it is important to know what doctors watch for.

Possible complications include:

• Toxic megacolon

• Severe bleeding

• Bowel perforation

• Peritonitis

• Colonic stricture

• Increased risk of colorectal cancer

• Amyloidosis

The risk of colorectal cancer increases with longer disease duration and more extensive disease. Regular screening is therefore an important part of long-term care.

Colon Cancer Screening

People with ulcerative colitis may need regular colonoscopy screening.

Screening usually starts 8 to 10 years after the first diagnosis. If primary sclerosing cholangitis is diagnosed, screening starts at the time PSC is diagnosed.

The usual test is ileocolonoscopy with biopsies.

The interval may be every 1 to 5 years, depending on individual risk.

Ulcerative Colitis and Pregnancy

Many people with ulcerative colitis can have healthy pregnancies, especially when the disease is in remission.

Important points include:

• Fertility is usually not affected in women whose IBD is in remission and who have not had abdominal surgery.

• Active disease may reduce fertility.

• Active disease at conception increases the chance that disease remains active during pregnancy.

• Active disease is linked with a higher risk of preterm birth and low birth weight.

• Most medicines used for IBD can be continued during pregnancy.

• Methotrexate is an exception and should not be used at conception.

• Steroids may be used for flares but are not preferred for long-term maintenance during pregnancy.

Anyone planning pregnancy should discuss treatment with their healthcare team before trying to conceive.

What Is the Outlook?

On average, people with ulcerative colitis have a normal life expectancy.

The condition is long-term, and many people have periods of flare-ups and remission. With regular care, appropriate treatment, and screening, ulcerative colitis can often be managed effectively.

Key Takeaways

• Ulcerative colitis is a chronic inflammatory disease of the colon. It usually starts in the rectum and may spread through part or all of the colon.

  
  

• The most common symptom is bloody diarrhea, often with urgency, cramps, and frequent bowel movements.

  
  

• Diagnosis is confirmed with colonoscopy and biopsy. Blood and stool tests help assess inflammation, rule out infection, and monitor disease activity.

  
  

• Treatment depends on severity. Mild disease may be treated with 5-ASA medicines, while more severe disease may need steroids or immune-targeting medicines.

  
  

• Surgery can cure ulcerative colitis when medicines do not work or complications develop.

Regular follow-up is important, especially for monitoring complications and screening for colorectal cancer.