Ulcerative colitis: what happens when you have chronic inflammation of the colon
Bowel HealthInflammationMedical Conditions

Ulcerative colitis: what happens when you have chronic inflammation of the colon

Written by

Anna Roell
9 August, 2023

Medically checked article All HOMED-IQ content is reviewed by medical specialists

Ulcerative colitis is a chronic inflammatory bowel disease in which the lining of the large intestine (colon) and rectum become inflamed. Along with Crohn’s disease, ulcerative colitis belongs to a group of conditions called inflammatory bowel disease. Inflammatory bowel disease is characterized by chronic inflammation of the tissues lining the digestive tract, causing recurring episodes of abdominal pain, diarrhea, and other uncomfortable symptoms. Want to learn more about the causes, symptoms, diagnostic options and treatment options for ulcerative colitis? Read on to learn more.

Table of contents

What is ulcerative colitis?

Ulcerative colitis is a chronic disease that causes inflammation and ulcers in the lining of the colon and rectum. The colon is a part of the digestive system and is the last section of the intestine, while the rectum connects the colon to the anus. In ulcerative colitis, the inner wall of the colon or rectum becomes inflamed and small, open sores or ulcers form, bleeding or oozing mucus and pus. These inflammations and ulcers can cause severe discomfort.

Usually, continuous sections of the intestine are affected by ulcerative colitis, but the extent and location of inflammation can vary. In some people, only the last part of the bowel, the rectum, is affected by ulcerative colitis. In others, the disease may affect the entire colon and rectum.

What are the causes of ulcerative colitis?

The exact causes of ulcerative colitis are not completely understood. However, there are several known risk factors that may contribute to the development of the disease:

  • Autoimmune reaction: In an autoimmune disease, the immune system mistakenly attacks healthy cells of the body as if they were foreign substances. In ulcerative colitis, the immune system may attack the cells of the colon, causing an inflammatory response.
  • Genetic predisposition: studies have shown that individuals who have relatives with ulcerative colitis have an increased risk of developing the disease. This suggests that genetic factors may play a role.
  • Environmental factors: Certain environmental factors may also play a role in the development of ulcerative colitis. For example, the disease appears to be more common in Western countries, which could indicate differences in diet or exposure to certain environmental factors.
  • Smoking: Smoking appears to increase the risk of developing ulcerative colitis. Smokers have a higher risk of developing the disease, and their symptoms are often more severe than those of nonsmokers (Mahid et al., 2006).

It is important to emphasize that none of these factors alone explains the development of ulcerative colitis. It is likely a combination of these factors that lead to the development of the disease (NHS, 2022).

What are the symptoms of ulcerative colitis?

Ulcerative colitis is a systemic disease. This means that it does not exclusively affect the colon and rectum, but can also affect other parts of the body. Symptoms vary depending on the severity of the disease and may change over time.

Below are some of the most common symptoms of ulcerative colitis:

  • Bloody diarrhea: This is one of the main signs of ulcerative colitis. Blood is often noticed in the stool and is due to bleeding from ulcers in the colon.
  • Abdominal pain and cramping: These may occur due to inflammation and ulcers that form along the inner wall of the colon.
  • Urgency to have a bowel movement: Individuals with ulcerative colitis often have an urgent need to go to the bathroom that can come on quickly.
  • Weight loss: Unintentional weight loss can also be a sign of ulcerative colitis, as inflammation and pain can affect appetite, and diarrhea can impair your body’s ability to absorb nutrients.
  • Fatigue: Inflammation can lead to persistent fatigue and a general feeling of malaise.
  • Fever: In severe cases of ulcerative colitis, fever may occur.
  • Joint pain: ulcerative colitis may also cause symptoms outside the digestive system, including joint pain.

Source: Mayo Clinic, 2022

If you notice signs and symptoms that may indicate ulcerative colitis, be sure to see a doctor.

Does ulcerative colitis go away?

Ulcerative colitis is a chronic disease, which means it is long-lasting and can progress over time. There may be periods of “remission” in which symptoms improve or disappear completely, but these periods may be followed by “relapses” in which symptoms return or worsen.

The severity and duration of relapses can vary greatly from person to person, and some people may remain in remission for years, while others may have frequent relapses. Relapses can be triggered by a variety of factors, including stress, certain medications and foods, infections, and even hormonal changes (NIDDK, 2023; Cleveland Clinic, 2020).

What complications can occur with ulcerative colitis?

Ulcerative colitis can lead to a number of complications over time, both inside and outside the intestines. Some of these include:

  • Blood loss: Repeated inflammation and ulcers in the colon can cause significant bleeding and subsequent iron deficiency, leading to anemia.
  • Intestinal perforation: In severe cases, inflammation can cause the intestinal wall to weaken and rupture. This is a medical emergency and requires immediate surgery.
  • Toxic megacolon: This is a rare but serious complication in which the colon becomes extremely enlarged. Without prompt treatment, it can cause the bowel to rupture, which is life-threatening.
  • Increased risk of bowel cancer: Ulcerative colitis increases the risk of bowel cancer. The longer and more severe the inflammation in the colon, the greater the risk. Regular screening (colonoscopy) is therefore very important in patients with ulcerative colitis.
  • Liver disease: Ulcerative colitis can also lead to other liver diseases, including primary sclerosing cholangitis. In this disease, the bile ducts become inflamed and hardened, which can lead to severe liver damage.
  • Eye and skin diseases: Some people with ulcerative colitis may also develop inflammation of the eyes (e.g., uveitis) and skin (e.g., erythema nodosum)

Quelle: Felmann, 2023

It is important for people with ulcerative colitis to closely monitor their health and any worsening symptoms, and to seek prompt medical care for potential complications.

How is ulcerative colitis diagnosed?

Diagnosis of ulcerative colitis is usually made through a combination of medical history, physical examination, and diagnostic tests. These may include:

  • Blood tests: A complete blood count is often performed to detect anemia, which can result from bleeding in the intestines. C-reactive protein (CRP), an inflammatory marker in the body that is elevated when inflammation is present, is also measured. Certain antibodies that indicate ulcerative colitis may also be tested for.
  • Stool sample: A stool sample may be used to test for blood, infection, or inflammation in the intestines. It is also possible to check for the presence of hidden blood in the stool from home using Homed-IQ’s Bowel Cancer Screening Test.
  • Colonoscopy: This exam uses a long, flexible tube with a camera on the end to examine the inside of the colon. This may reveal inflammation, ulcers, early signs of bowel cancer, or other abnormalities.
  • Biopsy: During a colonoscopy, the doctor may take small samples of tissue to examine under a microscope. This can help confirm the diagnosis and rule out other possible causes of symptoms.

Source: Stanford Medicine, 2023

Would you like to check in on your own health from home?

Homed-IQ’s Inflammation Test allows users to measure the level of C-reactive protein (CRP) in the blood, a marker of inflammation in the body, from the comfort of your own home. It is also possible to check for anemia that could be caused by intestinal malabsorption or bleeding using the Anemia Test, which measures iron, ferritin, and hemoglobin. Homed-IQ’s test kits contain everything you need to take a sample from home. After collecting your sample, simply send the test kit back to Homed-IQ’s laboratory in the prepaid shipping box. The sample is then analyzed by a certified laboratory, with understandable results sent to your online account.

How is ulcerative colitis treated?

Treatment for ulcerative colitis aims to relieve symptoms, reduce inflammation, and prolong periods of remission. This may include medication, diet and lifestyle changes, and in severe cases, surgery.

  • Medications: The type of medication prescribed depends on the severity of symptoms and the extent of the disease. These include anti-inflammatory medications, immunosuppressants, and steroids that target different aspects of the immune system and inflammatory process.
  • Diet: There is no specific diet for people with ulcerative colitis, but certain dietary changes can help relieve symptoms and reduce inflammation. Some people find that they need to avoid certain foods that promote inflammation because they can make symptoms worse. These can include sugary, fatty, and highly spiced foods, as well as caffeinated and alcoholic beverages. A balanced diet rich in minerals and vitamins is important to support general health and prevent deficiency symptoms. Anti-inflammatory foods can also be helpful.
  • Lifestyle: Lifestyle changes can also help in managing ulcerative colitis. These include getting enough sleep, exercising regularly, and managing stress in a healthy way. Stress leads to the release of the hormone cortisol, which can lead to ongoing inflammatory responses if chronic stress is present. For this reason, cortisol and stress levels should be kept low if possible.
  • Surgery: In severe cases, medications and lifestyle changes may not be sufficient and surgery may be necessary. Surgery may involve removal of part or all of the colon.

Sources: NHS, 2022; Cleveland Clinic, 2020


Ulcerative colitis is a chronic inflammatory bowel disease that mainly affects the colon and causes symptoms such as diarrhea, abdominal pain, and fatigue. Its exact cause is unknown, but it appears to be triggered by a combination of genetic, immunologic, and environmental factors. Diagnosis and treatment require close medical monitoring as well as diet and lifestyle adjustments to relieve symptoms and prevent complications.


Mahid, S., & et al. (2006). Smoking and Inflammatory Bowel Disease: A Meta-analysis. Mayo Clinic Proceedings, 81(11), 1462-1471. https://www.sciencedirect.com/science/article/pii/S0025619611612536

Ulcerative colitis – Causes. (n.d.). NHS. Retrieved July 7, 2023, from https://www.nhs.uk/conditions/ulcerative-colitis/causes/

Ulcerative Colitis Diagnosis. (n.d.). Stanford Health Care. Retrieved July 7, 2023, from https://stanfordhealthcare.org/medical-conditions/digestion-and-metabolic-health/ulcerative-colitis/diagnosis.html

Ulcerative colitis – Symptoms and causes. (2022, September 16). Mayo Clinic. Retrieved July 7, 2023, from https://www.mayoclinic.org/diseases-conditions/ulcerative-colitis/symptoms-causes/syc-20353326

Ulcerative Colitis: Symptoms, Treatment & Living With It & Diagnosis. (2020, April 23). Cleveland Clinic. Retrieved July 7, 2023, from https://my.clevelandclinic.org/health/diseases/10351-ulcerative-colitis

About the author

Anna Roell

Anna is a trained nurse and health economist specializing in epidemiology, combining her medical and scientific interests. Her goal is to improve others' understanding of medical information and to communicate it in an understandable way. Anna is originally from Germany and now lives in Amsterdam. What she appreciates most about Amsterdam is the open-minded, active attitude of the people, the markets, and the beautiful nature in the areas surrounding Amsterdam.