Last Updated on June 30, 2023 by Steven Root

Ulcerative colitis is a chronic, autoimmune disease of the large intestine. In this article, we will explore the:

  • Gastrointestinal Symptoms
  • Systemic Symptoms
  • Types of Ulcerative Colitis
  • Risk Factors
  • Complications
  • When to See a Doctor

Gastrointestinal Symptoms

Ulcerative colitis often presents first and foremost as disturbances in gastrointestinal function (source). The most common ulcerative colitis symptoms include:

  • Diarrhea, which may become persistent and may also include blood or pus
  • Rectal pain and bleeding, frequently occurring prior to a bowel movement
  • Urgency to defecate, sometimes accompanied by an inability to defecate
  • Abdominal pain and cramping, which can vary in severity
  • Weight loss due to reduced appetite or poor absorption of nutrients

Systemic Symptoms

Beyond the gastrointestinal tract, ulcerative colitis can also produce systemic symptoms that can appear unrelated to the digestive tract. These reflect the body’s overall response to inflammation (source). These symptoms include:

  • Fatigue and malaise, which can be quite pronounced and impair daily function
  • Fever, particularly during severe bouts of inflammation
  • Anemia, resulting from chronic blood loss in the stool
  • Dehydration, secondary to severe diarrhea

Types of Ulcerative Colitis

Different types of ulcerative colitis affect various parts of the colon, contributing to variation in symptoms and also the associated treatment approaches (source). The major types include:

Ulcerative Proctitis

Ulcerative proctitis is a form of ulcerative colitis where the inflammation is confined to the rectum. This is generally considered the mildest form of the disease.

Symptoms primarily involve rectal bleeding and rectal pain, often experienced as a constant urge to have a bowel movement. However, patients might also experience periods of constipation.

Despite its classification as the milder form, ulcerative proctitis should not be taken lightly. Continuous monitoring and treatment are necessary to manage symptoms and prevent progression of the disease.


In proctosigmoiditis, inflammation extends from the rectum to the sigmoid colon, which is the lower segment of the colon that connects the descending colon to the rectum.

Common symptoms of proctosigmoiditis include bloody diarrhea, abdominal cramps, and an urgent need to defecate, often leading to tenesmus, a sensation of incomplete evacuation. Some individuals may also experience unexplained weight loss and fatigue.

As with all forms of ulcerative colitis, the severity and frequency of symptoms can vary significantly among individuals.

Left-sided Colitis

Left-sided colitis is characterized by inflammation that starts at the rectum and extends upward through the sigmoid and descending colon, all of which are located on the left side of the abdomen. Hence the name, left-sided colitis.

Symptoms often include bloody diarrhea, abdominal cramping on the left side, unintended weight loss, and a decrease in appetite.

Since a larger area of the colon is affected in this type, symptoms can be more severe and extensive than in ulcerative proctitis and proctosigmoiditis.


Pancolitis refers to a form of ulcerative colitis where the entire colon, from the rectum to the cecum, is affected.

This is the most severe type of ulcerative colitis and it often presents with significant symptoms including chronic bloody diarrhea, severe abdominal pain, fatigue, and substantial weight loss.

Pancolitis can also cause systemic symptoms like fever, night sweats, and anemia due to chronic blood loss.

Given the severity and the systemic nature of the symptoms, individuals with pancolitis will often require stringent medical supervision and care.

Risk Factors

Several risk factors can increase the likelihood of developing ulcerative colitis. Some of the most significant ones include (source):

  • Age: Most people are diagnosed before the age of 30
  • Family History: Those with a family member with ulcerative colitis are at increased risk
  • Race/Ethnicity: Caucasians and people of Ashkenazi Jewish descent have the highest risk
  • Genetic susceptibility: several key genes are associated with ulcerative colitis
  • Environmental risks: certain environmental factors seem to increase risk
  • Poor diet: enquire here for help in designing a diet to mitigate against ulcerative colitis symptoms.


Ulcerative colitis is a serious condition that can lead to life-threatening complications if not managed properly (source). Complications may include:

Severe Bleeding

Severe bleeding is one of the most serious complications associated with ulcerative colitis. This typically occurs as a result of prolonged inflammation and ulceration of the colon, leading to damage to the blood vessels in the colon walls.

This may also lead to iron deficiency anemia, a condition characterized by a lack of sufficient red blood cells to carry oxygen to your body’s tissues. Prolonged, unchecked bleeding requires immediate medical attention to prevent further complications.

A Hole in the Colon (Perforated Colon)

A perforated colon is another significant complication of ulcerative colitis. It refers to the development of a hole in the wall of the colon. It is caused by severe and prolonged inflammation that weakens the colon wall.

A perforated colon is a medical emergency as it allows the contents of the colon, including bacteria, to spill into the abdominal cavity. This can lead to peritonitis, a severe infection that can be life-threatening if not treated promptly.

Toxic Megacolon

Toxic megacolon is a rare, but potentially deadly complication of ulcerative colitis. It involves the rapid swelling of the colon, which can lead to its rupture if not treated immediately.

Symptoms may include abdominal pain and bloating, fever, rapid heart rate, and shock.

Seek immediate medical attention if toxic megacolon is suspected as it can lead to septicemia, a serious bloodstream infection, if the colon ruptures.

Severe Dehydration

Dehydration is a common complication of ulcerative colitis, particularly during flare-ups of the disease when diarrhea is severe.

Chronic diarrhea can lead to a significant loss of fluids and electrolytes, which are essential for maintaining the body’s balance of fluids. If not adequately replaced, this can lead to dehydration, characterized by extreme thirst, fatigue, dizziness, and confusion.

In severe cases, dehydration can impact kidney function and may require hospitalization.

Liver Disease (Rare)

Though rare, liver disease can occur in people with ulcerative colitis.

The most common liver disorder associated with ulcerative colitis is primary sclerosing cholangitis, a condition characterized by inflammation, scarring, and eventual destruction of the bile ducts inside and outside the liver. Over time, this can lead to liver damage and potentially liver failure.

Increased Risk of Colon Cancer

People with ulcerative colitis are at an increased risk of developing colon cancer as a result of the chronic inflammation associated with the condition. The risk increases with the duration of the disease, as well as with how much of the colon is affected.

Regular screenings for colon cancer, including colonoscopies, are recommended for individuals with ulcerative colitis to allow for early detection and treatment.

When to See a Doctor

Anyone experiencing persistent diarrhea, abdominal pain, rectal bleeding, or unexplained weight loss should seek medical attention (source). These are hallmark ulcerative colitis symptoms that warrant evaluation by a healthcare professional.

In Summary

We have discussed that:

  • Ulcerative colitis symptoms span both gastrointestinal and systemic signs.
  • There are multiple types of ulcerative colitis, each with unique symptom profiles.
  • Risk factors include age, family history, racial/ethnic backgrounds, genetics, and environment
  • Complications of ulcerative colitis can be severe, highlighting the importance of proper management.
  • Individuals should see a doctor if they are experiencing any of the main symptoms of ulcerative colitis.