The main symptoms of ulcerative colitis

Ulcerative colitis causes inflammation in your colon and rectum, which leads to belly pain, bloody diarrhea, and an urgent need to have bowel movements. The symptoms vary widely — some people have mild discomfort and a few loose stools a day, while others experience severe cramping, frequent trips to the bathroom, and bleeding that affects their daily life.

The hallmark sign is diarrhea mixed with blood or mucus. You may also feel an urgent need to go to the bathroom, sometimes waking you at night. Between flares — periods when symptoms worsen — you might feel almost normal, or symptoms may stay mild but never fully disappear.

Key Takeaways

  • Bloody or mucus-filled diarrhea is the most common symptom, often accompanied by belly cramping and an urgent need to have bowel movements.
  • Symptoms range from mild (a few loose stools daily) to severe (frequent urgent trips, heavy bleeding, and intense pain), and they vary from person to person.
  • Flares — periods when symptoms suddenly worsen — can last days or weeks, with quieter periods in between.
  • Symptoms beyond the digestive tract, such as joint pain, eye redness, or skin rashes, can occur in some people with ulcerative colitis.
  • Keeping track of when symptoms start, what they feel like, and what makes them better or worse helps your doctor understand your pattern.

Belly pain and cramping

Cramping and abdominal pain are common, especially during a flare. The pain usually happens before or during a bowel movement and may ease afterward. Some people describe it as a constant ache; others feel sharp cramps that come and go.

The severity depends on how much of your colon is inflamed. If inflammation is limited to the lower part of your colon and rectum, pain may be mild or localized to the lower belly. More widespread inflammation typically causes more intense pain across a larger area.

Diarrhea and bowel movement changes

Diarrhea is almost always present in ulcerative colitis. You may have anywhere from four to eight loose stools a day during a mild flare, or 10 to 20 or more during a severe one. The stool often contains visible blood, mucus, or both.

You may also feel an urgent, sometimes uncontrollable need to have a bowel movement — even when there is little stool in your colon. This urgency can happen at night, interrupting sleep. Some people experience tenesmus, which is the feeling that you need to go even though you have just gone.

Blood and mucus in stool

Visible blood in the toilet or on toilet paper is one of the first signs many people notice. The blood comes from the inflamed lining of your colon and rectum. In mild cases, you may see only small streaks; in severe flares, the stool may be mostly blood.

Mucus in the stool is also common because the inflamed intestinal lining produces extra mucus. You may see it mixed with stool or notice it on its own. The presence of blood and mucus together is a strong indicator of ulcerative colitis, though only a doctor can confirm the diagnosis.

Symptoms that come and go in flares

Ulcerative colitis does not cause constant, unchanging symptoms for most people. Instead, you experience flares — periods lasting days to weeks when symptoms suddenly get worse — followed by quieter periods when symptoms improve or nearly disappear. Some people go months between flares; others have them several times a year.

During a flare, you might go from having one or two loose stools a day to having 10 or more, with increased pain and bleeding. Between flares, you may have normal or near-normal bowel movements and little to no pain. Learning to recognize what triggers your flares — stress, certain foods, infections, or stopping medication — can help you and your doctor manage the condition.

Symptoms beyond the digestive tract

Some people with ulcerative colitis experience symptoms outside the digestive system. These can include joint pain or swelling (especially in the knees, ankles, or wrists), eye redness or pain, skin rashes or sores, or mouth ulcers. These symptoms may appear during a flare or independently of bowel symptoms.

Fever and fatigue are also common, particularly during active flares. The fatigue can be severe and may result from blood loss, inflammation, or the body's immune response. If you notice any of these symptoms alongside your bowel changes, mention them to your doctor — they help paint a complete picture of how ulcerative colitis is affecting you.

When symptoms suggest you need medical attention

Contact your doctor if you develop bloody diarrhea, persistent belly pain, or an urgent need to have bowel movements that lasts more than a few days. You should also reach out if your symptoms suddenly worsen, if you develop a fever, or if you notice blood in your stool for the first time.

Seek immediate care if you have severe abdominal pain, heavy rectal bleeding, signs of dehydration (extreme thirst, dark urine, dizziness), or a fever above 102°F. These can signal a serious flare or a complication that needs prompt attention. Do not wait to see if symptoms improve on their own if they are severe or new.

Keeping track of your symptoms

Writing down when symptoms start, how long they last, what they feel like, and what seems to make them better or worse gives your doctor valuable information. Note the number of bowel movements per day, whether there is blood or mucus, the level of pain on a scale of 1 to 10, and any other symptoms like fatigue or joint pain.

Also record what you ate, your stress level, whether you took your medication as prescribed, and any other life changes around the time symptoms shifted. Over time, patterns often emerge — certain foods, stress, or missed doses may consistently trigger flares. This record becomes a tool for managing your condition and helps your doctor decide whether your current treatment plan is working.

Frequently Asked Questions

Can you have ulcerative colitis without bloody stools?

It is uncommon but possible. Some people, especially in the early stages or during mild disease, may have diarrhea and cramping without visible blood. However, blood is present in most cases — your doctor may find it during an examination or through a stool test even if you do not see it yourself.

How often do flares happen?

Flare frequency varies greatly. Some people have one or two flares per year; others have several. Between flares, symptoms may disappear completely or remain mild. Your doctor can help you identify patterns in your own flares and discuss ways to reduce how often they occur.

Is ulcerative colitis pain always in the lower belly?

Pain is often in the lower belly and rectum, but it can occur anywhere in the colon depending on where inflammation is present. If inflammation extends higher up, you may feel pain in the middle or left side of your abdomen. Your doctor can determine the extent of inflammation through testing.

Can stress trigger ulcerative colitis symptoms?

Stress does not cause ulcerative colitis, but it can trigger or worsen flares in some people. If you notice symptoms flare during stressful periods, managing stress through exercise, relaxation, or counseling may help. Talk with your doctor about stress management strategies that might work for you.

What is the difference between ulcerative colitis symptoms and irritable bowel syndrome?

Ulcerative colitis causes visible blood in stool, inflammation of the colon lining, and often fever or weight loss. Irritable bowel syndrome (IBS) causes cramping and diarrhea but no blood, inflammation, or fever. Only a doctor can tell the difference through examination and testing — do not assume symptoms are IBS without being evaluated.