Navigation thread
Navigation thread
Inflamatory Bowel Disease
Make a donation
Make a donation
Joint project with . This link opens in a new tab.

What is Ulcerative Colitis?

Reading time: 1 min

Ulcerative colitis is a chronic inflammatory disease that affects only the innermost lining of the colon. The severity and extension of inflammation varies in each patient.

It can affect the following areas:

  • Proctitis. Affects just the rectum.
  • Left-sided colitis. Affects just the left colon (up to the splenic flexure).
  • Extensive colitis. Affectation up to the transverse colon. 
  • Pancolitis. Affects the entire colon. 

Most frequent symptoms of Ulcerative Colitis

Person standing with diarrhoea cramps

Diarrhoea.

Blood in the stool

Stools containing mucus and/or blood (hematochezia) or isolated emission of blood (rectal bleeding).

Numerous and small stools

Small volume stools (sputum) and/or feeling of incomplete evacuation (straining).

Person going to a toilet with frequent urge to evacuate

Frequent and urgent need to defecate.

Abdominal pain at night due to nocturnal bowel movements

Nocturnal stools.

Standing person holding hands to abdomen because of cramps

Abdominal pain (colic) or cramps.

Thermometer with a danger signal indicating fever

Fever, abdominal pain and poor overall health (due to fatigue, loss of appetite and weight loss) are all indicative of the condition’s severity.

Complications associated with Ulcerative Colitis

Toxic megacolon is a severe complication in which the colon’s diameter dilates by more than 6–7 cm and may even lead to rupture. Fortunately it is very rare since therapy is rapidly intensified in cases of severe ulcerative colitis that do not respond to conventional treatment.

The warning signs for this complication are fever, tachycardia, bloating and intense abdominal pain.

The condition can be diagnosed with a plain film abdominal X-ray.

Hemorrhage (bleeding) can also be a serious complication of ulcerative colitis.

Read more Crohn’s disease
Joint project with . This link opens in a new tab.

Substantiated information by:

Ingrid Ordas Jimenez
Irene Vinagre Torres
Marta Gallego Barrero

Published: 20 February 2018
Updated: 7 May 2025

The donations that can be done through this webpage are exclusively for the benefit of Hospital Clínic of Barcelona through Fundació Clínic per a la Recerca Biomèdica and not for BBVA Foundation, entity that collaborates with the project of PortalClínic.

Subscribe

Receive the latest updates related to this content.

Thank you for subscribing!

If this is the first time you subscribe you will receive a confirmation email, check your inbox

An error occurred and we were unable to send your data, please try again later.

Inflamatory Bowel Disease related news