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Different type of colitis: Colitis: Types, Diagnosis, and Treatment

Colitis: Types, Diagnosis, and Treatment

Colitis occurs when your large intestine is inflamed. It can cause pain and other symptoms, including ulcers, bloating, and diarrhea. Different types of colitis require different treatments.

Colitis is inflammation of your colon, also known as your large intestine. If you have colitis, you’ll feel discomfort and pain in your abdomen. This discomfort may be mild and reoccurring over a long period of time, or severe and appearing suddenly.

There are different types of colitis, and treatment varies depending on what type you have.

The types of colitis are categorized by what causes them.

1. Ulcerative colitis

Ulcerative colitis (UC) is one of two conditions classified as inflammatory bowel disease. The other is Crohn’s disease.

UC is a lifelong disease that causes inflammation and bleeding ulcers within the inner lining of your large intestine. It generally begins in the rectum and spreads to the colon.

UC is the most commonly diagnosed type of colitis. It occurs when the immune system overreacts to bacteria and other substances in the digestive tract, but experts don’t know why this happens.

Common types of UC include:

  • proctosigmoiditis, which affects the rectum and lower portion of the colon
  • left-sided ulcerative colitis, which affects the left side of the colon beginning at the rectum
  • pancolitis, which affects the entire large intestine

2. Pseudomembranous colitis

Pseudomembranous colitis (PC) occurs from overgrowth of the bacterium Clostridium difficile (C. diff). This kind of bacteria normally lives in the intestine, but it doesn’t cause problems because it’s balanced by the presence of “good” bacteria.

Certain medications, especially antibiotics, may destroy healthy bacteria. This allows C. diff to take over, releasing toxins that cause inflammation.

3. Ischemic colitis

Ischemic colitis (IC) occurs when blood flow to the colon is suddenly cut off or restricted. Blood clots can be a reason for sudden blockage. Atherosclerosis, or buildup of fatty deposits in the blood vessels that supply the colon, is usually the reason for returning IC.

This type of colitis is often the result of underlying conditions. These may include:

  • vasculitis, an inflammatory disease of the blood vessels
  • diabetes
  • colon cancer
  • dehydration
  • blood loss
  • heart failure
  • obstruction or blockage
  • trauma or injury

Although it’s rare, IC may occur as a side effect of taking certain medications such as fibrates and nonsteroidal anti-inflammatory drugs (NSAIDs). More research is needed to fully understand all medications that could be a contributing factor.

4. Microscopic colitis

Microscopic colitis is a medical condition that a doctor can only identify by looking at a tissue sample of the colon under a microscope. A doctor will look for signs of inflammation, such as lymphocytes, which are a kind of white blood cell.

Doctors sometimes classify microscopic colitis into two categories: lymphocytic and collagenous colitis.

Lymphocytic colitis is when a doctor identifies a significant number of lymphocytes. However, the colon tissues and lining are not abnormally thickened.

Collagenous colitis occurs when the colon’s lining becomes thicker than usual due to a buildup of collagen under the outermost layer of tissue.

Doctors do not know exactly what causes microscopic colitis. However, they do know some people are more at risk for the condition. People at a higher risk include:

  • current smokers
  • those assigned female at birth
  • those with a history of an autoimmune disorder
  • people older than age 50
  • people taking certain medications, such as some types of:
    • proton pump inhibitors (PPIs)
    • selective serotonin reuptake inhibitors (SSRIs)
    • nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin

The most common symptoms of microscopic colitis are:

  • chronic watery diarrhea
  • abdominal bloating
  • abdominal pain


Allergic colitis in infants

Allergic colitis is a condition that can occur in infants, usually within the first months after birth. The condition can cause symptoms in infants including:

  • reflux
  • excessive spitting up
  • fussiness
  • possible flecks of blood in a baby’s stool

Doctors don’t know exactly what causes allergic colitis. One of the most popular theories is that infants with allergic colitis have an allergic or hypersensitive reaction to certain components in breast milk. A 2020 review of studies indicated that a protein allergy, either through breast milk, cow’s milk, or formula, could contribute.

Eosinophilic colitis is a type of allergic colitis that can also show up in infants with these symptoms. Its causes are similarly unknown, but it’s likely also related to a protein allergy.

Doctors will often recommend an elimination diet for the birthing parent, which involves slowly cutting out certain foods known to contribute to allergic colitis. Examples include cow’s milk, eggs, and wheat. If the baby stops having symptoms of allergic colitis, these foods were likely causing the problem.

In severe cases, monoclonal antibodies, such as those used to help treat inflammatory bowel disease (IBD), may also be another treatment option.

Additional causes

Other causes of colitis include infection from parasites, viruses, and food poisoning from bacteria. You may also develop the condition if your large intestine has been treated with radiation.

Different risk factors are associated with each type of colitis.

You’re more at risk for UC if you:

  • are between the ages of 15 and 30 (most common) or 60 and 80
  • are white or of Ashkenazi Jewish descent
  • have a family member with UC

You’re more at risk for PC if you:

  • are taking long-term antibiotics
  • are hospitalized
  • are receiving chemotherapy
  • are taking immunosuppressant drugs
  • are older
  • have had PC before

You’re more at risk for IC if you:

  • are over age 50
  • have or are at risk of heart disease
  • have heart failure
  • have low blood pressure
  • have had an abdominal operation

Depending on your condition, you may experience one or more of the following symptoms:

  • abdominal pain or cramping
  • bloating in your abdomen
  • unexpected weight loss
  • diarrhea with or without blood
  • blood in your stool
  • urgent need to move your bowels
  • chills or fever
  • vomiting

A doctor may ask about the frequency of your symptoms and when they first started. The doctor will perform a thorough physical exam and use diagnostic tests such as:

  • colonoscopy, which involves threading a camera on a flexible tube through the anus to view the rectum and colon
  • sigmoidoscopy, which is similar to a colonoscopy but shows only the rectum and lower colon
  • stool samples
  • abdominal imaging such as MRI or CT scans
  • ultrasound, which can be useful depending on the area being scanned
  • barium enema, an X-ray of the colon after it’s injected with barium, which helps make images more visible

Treatments aim to reduce symptoms and can vary by factors such as:

  • type of colitis
  • age
  • overall physical condition

Bowel rest

Limiting what you consume by mouth can be useful, especially if you have IC. Taking fluids and other nutrition intravenously may be necessary during this time.


Your doctor may prescribe various medications to help manage colitis symptoms. These may medications include:

  • anti-inflammatory medication such as 5-aminosalicylates or corticosteroids to treat swelling and pain
  • immune system suppressors such as tofacitinib (Xeljanz), azathioprine (Azasan, Imuran), or cyclosporine (Gengraf, Neoral, Sandimmune)
  • biologics such as infliximab (Remicade), adalimumab (Humira), and ustekinumab (Stelara)
  • antibiotics to treat infection
  • pain medications
  • antidiarrheal medications
  • antispasmodic drugs
  • supplements for nutritional deficiencies


Surgery for colitis could include removing part or all of your colon or rectum. This may be necessary if other treatments don’t work. These surgeries could include:

  • ileal pouch-anal anastomosis (IPAA), in which the ileum (the end of the small intestine) is turned into a pouch that then connects to the anal canal
  • proctocolectomy, in which the colon (and sometimes the rectum) are removed
  • ileostomy, in which the ileum is connected to the abdominal wall, and a stoma (an opening in the abdomen) is created to allow waste to leave the body
  • continent ileostomy, in which the end of the ileum is secured inside the interior of the abdomen. This is a possible but uncommon surgical procedure for colitis.

The only definitive way to prevent a colitis flare-up is to have surgery. If you’re looking to prevent flare-ups without surgery, there are ways to decrease their likelihood:

  • Keep a food log to track which foods may cause an increase in symptoms.
  • Ask your doctor if you should change your fiber intake and how much to eat.
  • Ask your doctor if eating smaller meals more frequently will help you.
  • Increase your activity levels if you can.
  • Learn ways to help manage stress such as meditation, yoga, and mindfulness exercises.
  • Always take medications as prescribed and tell your doctor if you have not.
  • Make sure your doctor knows about all of your other medications and supplements, including vitamins.

Always check with your doctor before changing your diet or adding any new supplements.

While every person may experience diarrhea and abdominal cramps from time to time, speak with a doctor if you have diarrhea that does not seem to be related to an infection, fever, or any known contaminated foods.

Other symptoms that indicate it’s time to see a doctor include:

  • joint pain
  • rashes that have no known cause
  • small amount of blood in your stool, such as slightly red-streaked stool
  • stomach pain that keeps coming back
  • unexplained weight loss

Seek immediate medical attention if you see a significant amount of blood in your stool.

In all cases, early detection is critical to recovery. Early detection may help prevent other serious complications.

If you feel that something is not right with your stomach, it’s best to talk with a doctor. Listening to your body is important to staying well.

Read this article in Spanish.

Symptoms, Triggers, Treatment, and More

Colitis occurs when your colon, or large intestine, is inflamed.

Microscopic colitis is a type of colitis that’s best identified by looking at colon cells under a microscope. The main subtypes of microscopic colitis are collagenous colitis and lymphocytic colitis.

In collagenous colitis, a thick layer of collagen — a type of connective protein — forms within the colon tissue. Its symptoms can disappear and reappear.

Lymphocytic colitis occurs when the colon contains a large number of lymphocytes, which are types of white blood cells. Learn more about it and other forms of colitis.

The symptoms of collagenous colitis can come and go, and vary in severity.

The most common symptoms include:

  • chronic watery diarrhea, which can appear and disappear over a period of weeks, months, or years
  • abdominal pain
  • abdominal cramps

Less common symptoms include:

  • dehydration
  • weight loss
  • bloating
  • flatulence or gas
  • nausea
  • vomiting
  • fatigue
  • an urgent need to go to the bathroom
  • fecal incontinence

Like many other gastrointestinal conditions, the exact cause of collagenous colitis is unknown. Research indicates that it likely has a genetic basis and could be related to autoimmune conditions.

Some possible causes of collagenous colitis include:

  • genetic abnormalities
  • autoimmune conditions such as rheumatoid arthritis, psoriasis, and Crohn’s disease
  • certain bacteria or viruses
  • smoking

Collagenous colitis isn’t contagious. It can’t spread to other people.

Medications as triggers

Medications that may trigger microscopic colitis and collagenous colitis include:

  • nonsteroidal anti-inflammatory drugs (NSAIDs)
  • selective serotonin reuptake inhibitors (SSRIs), the most commonly prescribed class of antidepressants
  • angiotensin-converting enzyme (ACE) inhibitors for high blood pressure
  • angiotensin II receptor blockers (ARBs) for high blood pressure, heart disease, or kidney disease

Research is mixed on the effects of the following medications:

  • statins for high cholesterol
  • protein pump inhibitors (PPIs) and h3 receptor blockers, which are used to treat acid reflux and GERD
  • oral medications for diabetes

Some research states that they have little to no effect on microscopic colitis, or may even be associated with lower rates of the condition.

Other studies indicate that these medications also trigger microscopic colitis and collagenous colitis.

According to a 2021 study, if these medications are associated with increased rates of microscopic colitis and collagenous colitis, it may be because they make diarrhea worse. A worsening case of diarrhea then prompts a doctor to make a diagnosis of colitis.

Collagenous colitis is more common among women than men. It’s also more common among people who are over 50 years old.

In addition, people who have celiac disease are more likely to have collagenous colitis.

Collagenous colitis may also be more common among people who currently smoke and people with a family history of the condition.

Researchers have noticed that the number of collagenous colitis cases is increasing. This may be because better detection is available and there’s increased awareness of the condition.

Collagenous colitis can only be diagnosed with a biopsy of the colon. You’ll likely also have a colonoscopy or sigmoidoscopy so that the doctor can better evaluate the health of your colon.

During the biopsy, a healthcare professional removes several small pieces of tissue from your colon. Then the tissues are examined under a microscope.

The common diagnostic process includes:

  • a medical history
  • colonoscopy with a biopsy
  • lab tests, such as blood and stool tests
  • imaging tests, such as CT scans, MRIs, or X-rays
  • endoscopy

Some tests and procedures are used to rule out other medical conditions that may cause similar symptoms, such as irritable bowel syndrome (IBS) and the infection Clostridium difficile (C. diff).

In some cases, collagenous colitis disappears on its own. However, some people need treatment.

Your treatment plan will depend on the severity of your symptoms.

Diet and lifestyle changes

Your doctor may recommend diet and lifestyle changes to help treat this condition. These changes are usually the first part of any treatment plan.

Common diet changes include:

  • eating a reduced fat diet
  • opting for a gluten-free diet
  • drinking more fluids to prevent dehydration from diarrhea
  • switching to a milk-free diet
  • avoiding food with artificial sweeteners
  • eliminating caffeine and lactose

Common lifestyle changes include:

  • quitting smoking, if you smoke
  • maintaining a moderate weight
  • maintaining a healthy blood pressure
  • exercising regularly


Your doctor will review the medications you currently take and make suggestions about either continuing or stopping them.

In 2016, the American Gastroenterological Association (AGA) released its guidelines on microscopic colitis. The AGA recommends starting with budesonide, a type of corticosteroid, before considering other medications.

Other medications your doctor may recommend to help treat the symptoms of collagenous colitis include:

  • antidiarrheal medications
  • intestinal anti-inflammatory medications, such as mesalamine (Apriso, Asacaol HD, Pentasa) or sulfasalazine (Azulfidine)
  • antibiotics
  • medications that block bile acids, such as cholestyramine (Prevalite)

The supplement psyllium may be recommended, too. Immunomodulators or anti-TNF (tumor necrosis factor) therapies may be used in extreme cases.

The Food and Drug Administration (FDA) hasn’t approved any medications for microscopic colitis or collagenous colitis. However, medications such as mesalamine and sulfasalazine are FDA approved for the treatment of ulcerative colitis.

If a doctor prescribes medications such as these for collagenous colitis, it’s considered an example of off-label drug use.


Off-label drug use means a drug that’s approved by the FDA for one purpose is used for a different purpose that hasn’t yet been approved.

However, a doctor can still use the drug for that purpose. This is because the FDA regulates the testing and approval of drugs, but not how doctors use drugs to treat their patients. So your doctor can prescribe a drug however they think is best for your care.


Your doctor may recommend surgery if diet and medication changes don’t help. Surgery is usually reserved for extreme cases. It’s not a typical treatment for collagenous colitis.

The most common types of surgery for collagenous colitis include:

  • colectomy, which means removing all or part of the colon
  • ileostomy, which means creating an opening in the abdomen after a colectomy

Collagenous colitis doesn’t cause blood in your stool, increase your risk of colon cancer, or have any effect on life expectancy. Symptoms may affect a person’s quality of life, but they’re not life threatening and won’t typically require emergency medical care.

However, it’s worth seeing a doctor if you have chronic watery diarrhea in combination with any of the common risk factors for collagenous colitis.

You’ll also want to see a doctor if you’re diagnosed with collagenous colitis and your recommended treatment plan doesn’t help reduce your symptoms.

Collagenous colitis can come and go, and relapses are common. You may need to try several treatments to find relief from the symptoms.

The time it takes to recover can vary. Some people may have symptoms for weeks, months, or years.

There are no current recommendations for preventing collagenous colitis. However, following the diet and medication changes recommended by your doctor may reduce your likelihood of having a relapse.

Read this article in Spanish.

Intestinal colitis – types, causes, symptoms, signs, complications, diagnosis, treatment, prevention











Colitis is an inflammatory disease of the colon mucosa. Signs of such an inflammatory process are frequent loose bloody stools, abdominal pain and fever. The causes of colitis can be very different, so this term in medicine hides several diseases that share common symptoms.

Infectious colitis

This is one of the most common variants of pathology that occurs at the time of activation of the conditionally pathogenic microflora located in the gastrointestinal tract. Most often, the disease is diagnosed in the summer, as well as while traveling to other countries.

Causes of development – bacteria, viruses, protozoa, including Koch’s bacillus, spirochete, fungus and dysbacteriosis. There are several forms of infectious inflammation of the large intestine – catarrhal, fibrinous, catarrhal-hemorrhagic, phlegmonous, phlegmonous-gangrenous and necrotic.

This type of colitis has certain symptoms, but they will depend on which microorganism has caused the inflammatory process. Common to all will be such manifestations as an acute onset, diarrhea, abdominal pain in the form of cramps, fever, deterioration of health. To identify what caused the disease, it is necessary to do a fecal analysis. This will help to prescribe specific treatment.

Ischemic colitis

Inflammation appears in the wall of the large intestine due to circulatory disorders, which can be acute or chronic. In a severe case and without timely treatment, this can cause necrosis. The main cause of circulatory disorders is blockage of the vessel by a thrombus. According to statistics, most cases of this pathology are diagnosed at the age of 50 years.

The size of the lesion will depend on the size of the occluded vessel, the duration of ischemia, and the speed at which a doctor is consulted. There is transient ischemia, in which all processes can be reversed without consequences, stenosing with the formation of a stricture, and gangrenous, when damage to the intestinal wall is irreversible and ends with tissue death.

Ulcerative colitis

Ulcerative colitis is a chronic inflammation of unknown origin. The main manifestation is the appearance on the mucous membrane of the large intestine of ulcers of various sizes and depths of the lesion. The disease proceeds in cycles with periods of exacerbation and remission.

Long-term ulcer pathology increases the risk of developing cancer by several times. It is most often diagnosed in women and occurs with a frequency of up to 80 cases per 100,000 people. Primary detection is typical in two age groups. The first group – young people aged 15 to 25 years, the second – people over 55 years old. For what reasons this form begins to form is still unknown, but doctors suggest two provoking factors – genetic and immune.

Radiation colitis

This species occurs in people who have undergone radiation therapy for the treatment of malignant tumors of the pelvis or intestines. However, not the entire large intestine is damaged, but only the sigmoid and rectum. According to the clinical picture, such inflammation is similar to an ischemic or ulcerative form.

Signs of radiation colitis do not develop immediately and begin to manifest themselves by the end of radiation therapy. The patient begins to complain of copious loose stools. The absorption of nutrients in the large intestine is severely impaired, which causes anemia, weight loss, and loss of appetite.

The risk of developing inflammation depends on the dose of radiation used, as well as the duration and location of exposure. An important role is played by the individual sensitivity of the organism to the level of increased radiation.

Toxic colitis

Often in adults there is toxic colitis, which is also called medicinal. This is one of the complications when taking certain groups of drugs. There are no specific symptoms that would help to quickly make a diagnosis, the main complaints are pain in the left half of the abdomen from below, profuse diarrhea, bloating, general weakness, fatigue.

Most often, this disease occurs against the background of taking antibacterial drugs, laxatives, cytostatics, NSAIDs, drugs for high blood pressure. Pathology against the background of taking medications can develop acutely or gradually. In some cases, toxic hepatitis or pancreatitis joins.

Spastic colitis

Colitis in children most often has the character of spastic. In addition to a painful attack, the patient complains of bloating, flatulence, rumbling in the abdomen. Belching may occur, diarrhea is characteristic, but in some cases, due to impaired motor skills, constipation is diagnosed. Against this background, there is no appetite, lethargy appears, body temperature may rise.

In infants, this disease develops against the background of artificial feeding. The child becomes restless, cries, tries to pull the legs to the stomach, strongly strains the muscles of the anterior abdominal wall. Other extraintestinal symptoms may also join – excessive sweating, headache, tachycardia.

Possible complications

Do not think that colitis is just an inflammatory disease. This is a serious pathology, which is dangerous for its many complications, and without treatment, they can appear at any time.

Most often, patients with colitis suffer from the following complications:

  • severe intestinal bleeding;
  • abrasion of the mucosa before the appearance of perforation;
  • dehydration;
  • osteoporosis;
  • inflammation of the skin, joints and eyes;
  • the likelihood of developing colon cancer;
  • development of toxic megacolon;
  • the risk of blood clots in the veins of the intestine.


To diagnose this pathology, it is necessary not only to pass urine, blood and feces tests, but also to undergo other examinations. Most often, patients are prescribed sigmoidoscopy. This method allows you to quickly and with great accuracy assess the condition of the mucosa, detect pinpoint hemorrhages on it, change in color and vascular pattern. Also, this method helps to take a biopsy for further analysis. It is used to diagnose colitis of the rectum and sigmoid colon.

Irrigoscopy is an x-ray technique that allows you to assess the location and size of the colon, its functional features and existing disorders. It is carried out using a contrast agent, and the result can be seen on a conventional x-ray.

Colonoscopy is a diagnostic method during which the doctor examines and evaluates the condition of the mucous surface of the large intestine. In addition to diagnosis, this method also allows you to take a biopsy and remove small polyps on the walls of the intestine.


Unfortunately, today there is no single treatment regimen for colitis of various origins. Therefore, all therapy is carried out depending on what provoked the disease.

For the infectious form, it will be taking antibiotics or antifungal drugs, depending on the sensitivity of the microflora. Replenishment of fluid is carried out using special solutions for drinking. Probiotics and prebiotics help to normalize the microflora, and sorbents remove toxins. Symptomatic therapy is prescribed depending on the symptoms present. Colitis pain is relieved with painkillers.

Ischemic colitis may require surgical treatment, and ulcerative colitis requires long-term therapy, diet and removal of the inflammatory process. Medicines for colitis in this case are prescribed only by a gastroenterologist, because the disease progresses rapidly, and surgery may be required in the later stages.

The toxic form requires a review of the dose of the drug taken, drug withdrawal or replacement with another. Spastic – treated with antispasmodics, enzyme preparations, enterosorbents and drugs that help relieve inflammation.


Inflammation of the colon is a very preventable disease. Prevention of colitis includes maintaining an active lifestyle, proper nutrition, avoiding fast food snacks and the mandatory inclusion of soups in the diet. It is recommended to always monitor the state of the psyche, try not to worry, treat stress and depression in a timely manner. It is necessary to observe hygiene measures, wash your hands more often and take tests for helminths once a year.

When the first unpleasant symptoms appear in the area of ​​the stomach or intestines, you should immediately contact a general practitioner or gastroenterologist.

The author of the article:

Nikitina Olga Ivanovna

therapist, gastroenterologist, KMN

work experience 24 years

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