Creeping fat is fat that wraps around your intestines. It’s common in people with Crohn’s disease and can often worsen symptoms. There’s little research on effective treatments, but anti-tumor necrosis factor (TNF) therapies may help.

We often think of fat as simply storage for extra calories we have ingested, but fat tissue does much more than that. Its roles are complex, affecting your body’s processes, including your immune system.

You have a layer of fat between your intestines and abdominal muscles called mesenteric fat. In some people with Crohn’s disease, this fat may begin to wrap around the inflamed intestines, sometimes leading to more severe symptoms. Doctors call this “creeping fat.”

Keep reading to learn more about creeping fat and what it means for people with Crohn’s disease.

Scientists and researchers don’t fully understand the relationship between creeping fat and Crohn’s disease yet. But the two seem to develop together.

Creeping fat begins in the layer of mesenteric fat between your abdominal muscles and organs. This fat starts to creep around individual intestines, like fingers, reaching into the muscle layer. The fat may reach more than halfway around the entire circumference of the intestine.

Some scientists consider the mesenteric fat and the intestine a single entity in conditions such as Crohn’s disease. This is because the mesentery begins to connect the different parts of the intestines. The mesenteric fat is full of blood and lymph vessels, allowing easy transport of cells and organisms between the intestinal segments.

But it also allows bacteria to move easily from one part of the intestines to the others.

Does creeping fat cause a change in appearance?

Creeping fat doesn’t typically affect your appearance. You can only detect it with imaging, such as MRI or CT scans.

Most of the fat you see on your body is subcutaneous fat, meaning it’s under the skin. Creeping fat is a type of visceral fat that’s deeper inside your body. Because visceral fat surrounds your organs, it has a more significant effect on your health.

Was this helpful?

In Crohn’s disease, the bacteria that usually live in your intestines don’t function as they should and allow opportunistic bacteria to invade. Bacteria may travel through the creeping fat to other parts of your intestine.

According to a 2020 study, creeping fat may develop as part of your body’s immune response to this overgrowth of bacteria. The creeping fat can help prevent the spread of a bacterial infection from your intestines to other parts of your body.

Research from 2018 suggested that creeping fat can promote inflammation in your intestines. This can lead to or worsen Crohn’s symptoms, such as:

As fat begins to creep out around your intestines, the inside of the intestines also begins to change. Creeping fat may be responsible for some Crohn’s disease complications, such as:

  • thickened intestinal muscle walls
  • strictures along the intestinal wall, causing obstructions
  • fibrosis or scarring
  • intestinal wall inflammation, leading to ulcers, masses, abscesses, or fistulas

Areas of creeping fat may indicate an area of particularly severe disease. These areas frequently need surgery to remove or resect the bowel. In one small 2018 study involving people with creeping fat on an MRI, 42% needed surgery within 2 years and 63% by the end of the study (a median follow-up time of just under 8 years).

Doctors can sometimes use imaging, like MRI or CT scans, to see creeping fat.

Typically, the only way to see the full extent of the condition is to visualize it during surgery. But a 2021 study found that using a CT scan with a contrast dye to detect vessels in the creeping fat was almost as accurate.

Not much research is available about treating creeping fat yet. According to the Crohn’s and Colitis Foundation, no definitive treatment exists yet. But researchers are looking for new ways to treat this condition.

Anti-TNF therapies, also called biological therapies, treat inflammation and autoimmune diseases. According to one small 2021 study, anti-TNF therapies may improve creeping fat and intestinal tissue health, reducing Crohn’s symptoms.

Creeping fat often suggests a more severe case of Crohn’s disease. It can lead to more severe symptoms and complications, such as bowel obstructions and ulcerations.

In one small 2018 study, 68% of people with Crohn’s disease developed severe bowel damage after 2 years of detecting creeping fat on an MRI, and 79% had bowel damage within 10 years.

But creeping fat may also indicate the most severe areas of intestinal inflammation. And it may prevent the infection from spreading further into your body.

How common is creeping fat in Crohn’s disease?

It’s unclear how many people with Crohn’s have creeping fat. But in one small 2018 study involving 90 people with Crohn’s disease, MRI revealed about 21.1% of people had creeping fat.

Can I prevent creeping fat?

There isn’t a lot of research into preventing creeping fat yet. Prevention may not be possible due to the cooperative nature of creeping fat and Crohn’s disease.

Do people with ulcerative colitis have Crohn’s disease?

Ulcerative colitis (UC) is the other common type of inflammatory bowel disease. Creeping fat is unique to Crohn’s disease and doesn’t show up in UC.

Creeping fat occurs when the layer of mesenteric fat covering your abdominal organs begins to creep around your intestines. This appears to be a protective response to an imbalance of bacteria due to Crohn’s disease, but it could lead to serious complications.

People with creeping fat in Crohn’s disease may experience worsened symptoms and complications such as strictures and scarring. No treatments are currently available to eliminate or reduce creeping fat, but anti-TNF therapies show promise.

Talk with a doctor about the role creeping fat may play in your Crohn’s disease experience.