What Are the First Symptoms of Ulcerative Colitis?

Medically Reviewed on 8/30/2022
ulcerative colitis (UC)
The first symptoms of ulcerative colitis (UC) may include cramp-like abdominal pain.

Ulcerative colitis (UC) is an inflammatory bowel disease that affects the lining of your colon and rectum and causes swelling and ulcers in your digestive tract. While there is no cure for the disease, it can be managed with proper medication and a healthy diet.

Initial symptoms

Symptoms of UC usually develop gradually over time. Initial symptoms may include the following:

  • Diarrhea that does not get better with probiotics and antibiotics
  • Loose or bloody stools 
  • Cramp-like abdominal pain that becomes intense during bowel movements
  • General feelings of being unwell, bloated, or constipated

Other symptoms

Other symptoms may include the following:

Rare symptoms

In rare cases, UC may cause the following:

What triggers ulcerative colitis symptoms?

Most people have mild to moderate symptoms. You may experience flare-ups followed by long periods of no symptoms.

Your symptoms may be triggered by an infection or an episode of acute stress. Consuming alcohol, caffeine, carbonated drinks, dried beans, or a high-fiber diet can also aggravate the condition.

What are the different classifications of ulcerative colitis?

Doctors often grade UC based on symptoms and blood work results, classifying the disease as mild, moderate, or severe.

Table: Classification of ulcerative colitis
Signs/Tests Mild UC Moderate UC Severe UC
Stools and cramps
  • 4 or fewer stools per day
  • With or without blood with mild cramps
  • More than 4 bloody motions per day
  • Mild cramps
  • More than 6 bloody motions per day
  • Severe cramps
Fever, elevated heart rate Absent Absent
  • Episodic fever temperature greater than or equal to 99.5 F
  • Tachycardia (Heart rate greater than or equal to 90 bpm)
Blood tests No anemia Mild anemia
  • Anemia (hemoglobin less than 10.5 g/dL)
  • An elevated Erythrocyte sedimentation rate (greater than or equal to 30 mm/hour)
Weight loss No weight loss No weight loss Rapid weight loss
Incidence 72% of patients have mild disease 27% of patients have moderate disease 1% of patients have severe disease at presentation


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What are complications of ulcerative colitis?

Your risk for UC complications is higher the more severe the disease. If symptoms are neglected, the following life-threatening complications can occur:

  • Anemia: Anemia occurs when the body has fewer red blood cells than normal, which can happen if stools are frequently bloody. Long-term anemia with a severe dip in hemoglobin can cause stress to the heart leading to heart failure.
  • Bone problems: Problems with vitamin D and calcium absorption due to gut swelling can cause bones to become brittle. This increases the risks of joint problems and even fractures.
  • Perforation: Untreated intestinal swelling in severe cases of ulcerative colitis may cause a tear or a hole in the wall of the large intestine. This can be life-threatening.
  • Shock: Passing a lot of blood from the rectum can cause low blood pressure and even shock.
  • Toxic megacolon: Extreme intestinal swelling can prevent regular intestinal movements, leading to paralysis of the intestine. This condition is potentially fatal.

Because this is a long-term disease with potential complications, it’s important to maintain regular follow-ups with your doctor.

Do I have an increased risk of cancer if I suffer from ulcerative colitis?

Unfortunately, yes. People with ulcerative colitis have a slightly elevated risk of developing colon cancer, and this risk increases with time:

  • 2% risk after 10 years
  • 8% risk after 20 years
  • 18% risk after 30 years

Your risk also increases if:

  • You have severe ulcerative colitis affecting large portions of the colon.
  • Symptoms start at a younger age.
  • You have a family history of colorectal cancer.
  • You have developed swelling in the biliary tree called primary sclerosing cholangitis.

Your doctor may suggest regular colon screenings via a colonoscopy. This is the only way to detect colon cancer in the early stages when it is still treatable. During a colonoscopy, a scope attached to a camera is inserted into the anus and moved upward, allowing your doctor to look for any suspicious masses in the colon or rectum.

Most doctors typically recommend colonoscopies every 1-3 years, starting 8 years after ulcerative colitis starts. If your doctor suspects that you may be at higher risk, they may recommend that you be checked on a more frequent basis.

Medically Reviewed on 8/30/2022
Peppercorn MA, Kane SV. "Clinical Manifestations, Diagnosis, and Prognosis of Ulcerative Colitis in Adults." UpToDate. <https://www.uptodate.com/contents/clinical-manifestations-diagnosis-and-prognosis-of-ulcerative-colitis-in-adults>.

United States. National Institute of Diabetes and Digestive and Kidney Diseases. "Definition & Facts of Ulcerative Colitis." National Institutes of Health. <https://www.niddk.nih.gov/health-information/digestive-diseases/ulcerative-colitis/definition-facts>.