Ulcerative colitis (UC) may cause crypt abscesses to form. Crypt abscesses occur when inflammatory cells accumulate in crypts, or pouches, inside the gastrointestinal system.

Ulcerative colitis is a form of inflammatory bowel disease (IBD). It occurs due to the immune system having an abnormal reaction that leads to inflammation and ulcers of the large intestine’s inner lining.

UC can cause a person to experience diarrhea, blood in their stool, and abdominal pain.

This article will explore what crypt abscesses are and the type of crypt abscesses that may occur. It will also explore how crypt abscesses may occur in UC and other causes of crypt abscesses and their treatments.

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The epithelial layer is the layer of cells that lines the organs, such as the large intestine and small intestine in the gastrointestinal (GI) tract. This layer folds back on itself to form a cavity or pouch, known as the crypt, which acts as a gland.

Crypt abscesses occur when there is a buildup of inflammatory cells within the crypts. The inflammatory cell accumulation can harm the surrounding cells and prevent the crypts from secreting substances and functioning effectively.

Small crypt abscesses may resolve less frequently on their own, while other types may require medication or surgical intervention.

Types of crypt abscesses

Two types of crypt abscesses may occur: neutrophilic and apoptotic.

Neutrophilic crypt abscesses contain white blood cells — neutrophils — that help the body fight infection. Apoptotic abscesses contain apoptotic cells that get rid of unneeded or abnormal cells, which is also known as programmed cell death.

In UC, inflammation normally begins in the rectum and progresses to the colon. Crypt abscesses form as a response to active inflammation. The abscesses are commonly neutrophilic in UC.

The destruction of the crypts can also cause the loss of the mucosal architecture, which leads to the colon becoming more rigid and short. It may take on a “lead-pipe” appearance.

When inflammation occurs with IBD, the crypts fill up with inflammatory white blood cells, including:

  • macrophages to remove dead and dying cells
  • neutrophils that attack bacteria
  • dendritic cells to produce immune responses against pathogens
  • natural killer T lymphocytes to destroy compromised cells

Read more about the immune system.

A doctor may diagnose a crypt abscess in a person with UC by taking a sample of the affected tissues, such as a part of the colon. This is known as a biopsy. A doctor will look at this sample under a microscope to see if there have been any structural changes to the cells.

In UC, a doctor may be able to see the formation of crypt abscesses and mucosal ulcers. These features may show the involvement of the mucosa and submucosa layers of the colon only. A biopsy may also show the presence of inflammatory cells, such as neutrophils, within the crypts.

Treatment for crypt abscesses may depend on how severe the person’s UC is.

Doctors prescribe mesalamine, or 5-aminosalicylic acid, to treat UC. This medication may help to reduce the incidence of inflammation within the GI tract by modulating the inflammatory response.

Mesalamine will lower the number of inflammatory cells by infiltrating the crypts. Untreated, these cells lead to abscesses.

Mesalamine is available as a capsule or tablet. However, a person may also administer it as an enema, foam, or suppository.

For a person with a more severe case of UC, a doctor may prescribe corticosteroids. Corticosteroids help to reduce the immune system’s over-activity and lower GI inflammation.

Read on about IBD from our dedicated hub.

Crypt abscesses can also occur as a result of other conditions or medications. Some of these are listed below.

Radiation for colon cancer

Colon or colorectal cancer occurs when unrestricted cell growth arises in the colon.

A doctor may treat colon cancer using radiation therapy. Radiation involves using high-energy particles or waves to damage or destroy cancer cells.

One of the side effects of this treatment type is that tissues within the body may absorb the high-frequency waves during radiation therapy. These waves may result in the body producing substances known as reactive oxygen species. These may cause apoptosis within cells.

The reactive oxygen species may also damage the crypts of the GI tract and may also result in inflammatory cells infiltrating the crypts and causing crypt abscesses.

Other conditions, infections, or medications may cause a crypt abscess. If one of these is the reason, a doctor will recommend a suitable line of treatment, such as:

Crohn’s disease

Crohn’s disease is another form of IBD. It leads to inflammation and irritation of the digestive tract and other symptoms, including diarrhea, cramping, and weight loss.

Treatment may include similar medications used to treat UC and immunomodulators, such as cyclosporine and methotrexate.


Treatment may involve the use of anti-inflammatory medication such as corticosteroids and sulphasalazine. More severe cases may require surgery. However, medical professionals may consider this a last resort due to the high rate of complications postsurgery.

Read more about Crohn’s disease surgery.


Infections may also cause crypt abscesses. For example, a person with Helicobacter pylori (H. pylori) or cytomegalovirus (CMV) infection may experience crypt abscesses.

Both infections may cause inflammation, leading to inflammatory cells infiltrating the crypts and abscesses.


Treatment for H. pylori may include a triple therapy of:

Meanwhile, treatment for CMV may include antiviral agents.


Some medications may cause crypt abscesses. For example, mycophenolate mofetil (MMF) is an immunosuppressant drug that treats autoimmune diseases, and doctors use it after organ and bone marrow transplants.

However, MMF also causes gastrointestinal symptoms in 45% of cases. The medication may cause crypt cell apoptosis, leading to crypt cell distortion and abscess.


A doctor may discontinue MMF in a person experiencing gastrointestinal symptoms. If symptoms do not improve, they may also prescribe a steroid such as prednisolone or infliximab.

Crypt abscesses occur when inflammatory cells build up in the crypts of the GI tract. Crypt abscesses can occur in UC due to inflammation in the colon and rectum.

A doctor may diagnose crypt abscesses in UC by taking a sample of the affected area and observing under a microscope for crypt changes and the presence of inflammatory cells.

Other causes of crypt abscesses include Crohn’s disease, radiation, medications, and infections, some of which have appropriate treatments recommended by doctors.