Table of ContentsView AllTable of ContentsWhat Is IC?Signs and SymptomsDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
What Is IC?
Signs and Symptoms
Diagnosis
Treatment
Indeterminate colitis (IC) is a diagnosis used to describe inflammatory bowel disease (IBD) when a person has features of IBD, but it’s not yet understood whether they have ulcerative colitis or Crohn’s disease.
This is a confusing and controversial topic in IBD, with broad implications for treatment. It’s estimated that between 10% and 15% of people with IBD are thought to have indeterminate colitis.In some situations, a diagnosis of another form of IBD might be made later as the condition changes.
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What Is Indeterminate Colitis?
IBDis often positioned as being an umbrella term that includesCrohn’s diseaseandulcerative colitis. There are major differences between thesetwo main forms of IBD:
In situations where a person has a type of IBD that can’t be classified into either of these descriptions, they may be diagnosed with indeterminate colitis.
This doesn’t mean that a diagnosis of Crohn’s disease or ulcerative colitis won’t be made in the future. It just means that the ongoing features of the disease don’t make the diagnosis clear.
The distinction can be unclear at any disease stage:
Indeterminate colitis continues to be debated in some circles and might even be considered subjective. Some researchers have made a case for indeterminate colitis being considered a third form of IBD, while others maintain that it is a stand-in term to be used until a firm diagnosis can be made.
How rare is indeterminate colitis?The prevalence rate of indeterminate colitis is about 22 cases per 100,000 people, and it has a higher incidence in females and Caucasian people.About 5% to 15% of people with IBD have been diagnosed with IC.
How rare is indeterminate colitis?
The prevalence rate of indeterminate colitis is about 22 cases per 100,000 people, and it has a higher incidence in females and Caucasian people.About 5% to 15% of people with IBD have been diagnosed with IC.
The prevalence rate of indeterminate colitis is about 22 cases per 100,000 people, and it has a higher incidence in females and Caucasian people.
About 5% to 15% of people with IBD have been diagnosed with IC.
Rather than being a mash-up of various characteristics of both ulcerative colitis and Crohn’s disease, indeterminate colitis is associated with a set of signs that was originally described in 1978—although there are no hard and fast rules.
Indeterminate colitis could have all or some of the attributes below.
Type of Ulcers
In ulcerative colitis, the ulcers found in the large intestine will only involve the most superficial layer of the mucosa, which lines the intestinal wall. If those ulcers are deeper than what would normally be expected with ulcerative colitis, and there’s no other indication that the disease is actually Crohn’s disease, it might lead to a preliminary diagnosis of indeterminate colitis.
These ulcers are sometimes described as transmural (meaning they go deep through the intestinal wall) or as being like fissures. In some cases, the fissure-like ulcers are narrow (about 13% of cases); sometimes they are shaped like a V (about 60% of cases).
Rectal Involvement
Another characteristic of indeterminate colitis is that the rectum is often not involved, or at least not fully involved.
In ulcerative colitis, the rectum tends to be inflamed in most cases. In Crohn’s disease, the rectum may or may not show inflammation.
Skip Lesions
In Crohn’s disease, inflammation may skip areas of the intestine, leaving a patchwork of inflamed areas between areas of healthy tissue. In ulcerative colitis, the inflammation begins in the rectum and continues up through the colon in a continuous pattern.
With indeterminate colitis, there may be areas that appear to be skipped over (i.e., free of inflammation).There could be several reasons this can happen, which is why this attribute can be another factor that doesn’t always help in making a solid diagnosis.
The definition of indeterminate colitisdoesn’t currently have standardization, although there are some broad guidelines.Part of the challenge is that the characteristics of indeterminate colitis can be different between people. In fact, IBD is a complicated disease that is difficult to classify.
There are some cases of indeterminate colitis that are thought of as “probable Crohn’s disease” while others are “probable ulcerative colitis.” This means there are patients in the indeterminate classification who could be anywhere on the entire spectrum between these two diseases.
Is indeterminate colitis an autoimmune disease?Since indeterminate colitis falls under the umbrella of IBD, which is recognized as an autoimmune condition, it too is considered an autoimmune disease where an overactive immune system attacks healthy tissue in the intestines, leading to inflammation.
Is indeterminate colitis an autoimmune disease?
Since indeterminate colitis falls under the umbrella of IBD, which is recognized as an autoimmune condition, it too is considered an autoimmune disease where an overactive immune system attacks healthy tissue in the intestines, leading to inflammation.
Change in Diagnosis
In most cases, a diagnosis of either Crohn’s disease or ulcerative colitis is eventually reached. When and why this happens is highly variable.
In some cases, if new inflammation crops up in the small intestine when there previously was only inflammation in the colon, adiagnosis of Crohn’s diseasecan be made.
Certain complications, either intestinal orextra-intestinal, are more common with one form of IBD over the other, and their presence can help in making a diagnosis.
In most cases, indeterminate colitis is treated with thesame medications and surgeries as ulcerative colitis.
However, if there is inflammation in the small intestine (such as the first part, called the ileum), then the approach might be similar to thetreatment of Crohn’s disease.
The treatment plan for indeterminate colitis might include these medications:
Surgical procedures for indeterminate colitis are also similar to that of ulcerative colitis and include ileal pouch-anal anastomosis or IPAA (more commonly called aJ-pouch) and ileostomy.
J-Pouch Surgery
Some people with indeterminate colitis undergo J-pouch surgery, which is typically reserved for use only in people who have anestablisheddiagnosis of ulcerative colitis.
Studies have shown that people with indeterminate colitis tend to do slightly less well with J-pouches than people who have ulcerative colitis. However, other researchers have pointed out that the failure rate of a J-pouch in people with indeterminate colitis could be high because the disease characteristics are not uniform—that is, there’s too much variability to study this group as a whole.
Ileostomy
During an ileostomy, the colon is removed and the end of the small intestine is brought through an incision in the abdomen (called a stoma).
A person with an ileostomy wears an appliance on the abdomen to catch stool, which leaves the body through the section of the small intestine that’s outside of the body.
Stool collects in the appliance and is emptied into the toilet as needed.
Summary
Indeterminate colitis is a diagnosis that’s used when IBD is present, but can’t be classified as ulcerative colitis or Crohn’s disease. With time, many people are diagnosed with ulcerative colitis or Crohn’s disease, which helps determine the best treatment and management options.
6 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Tontini GE, Vecchi M, Pastorelli L, Neurath MF, Neumann H.Differential diagnosis in inflammatory bowel disease colitis: state of the art and future perspectives.World J Gastroenterol. 2015;21(1):21–46. doi:10.3748/wjg.v21.i1.21Venkateswaran N, Weismiller S, Clarke K.Indeterminate Colitis - Update on Treatment Options. J Inflamm Res. 2021 Nov 30;14:6383-6395. doi: 10.2147/JIR.S268262Thurgate LE, Lemberg DA, Day AS, Leach ST.An overview of inflammatory bowel disease unclassified in children.Inflamm Intest Dis. 2019;4(3):97-103. doi:10.1159/000501519Crohn’s and Colitis Foundation.Medication options for Crohn’s disease.Crohn’s and Colitis Foundation.J-pouch surgery.American Cancer Society.What is an ileostomy?Additional ReadingGuindi M, Riddell RH. “Indeterminate colitis.“J Clin Pathol. 2004 Dec; 57: 1233–1244.Odze R. “Diagnostic problems and advances in inflammatory bowel disease.“Mod Pathol. 2003 Apr;16:347-358.Pezim ME, Pemberton JH, Beart RW Jr, et al. “Outcome of “indeterminant” colitis following ileal pouch-anal anastomosis.“Dis Colon Rectum. 1989 Aug; 32:653-658.Price AB. “Overlap in the spectrum of non-specific inflammatory bowel disease–‘colitis indeterminate’.“J Clin Pathol. 1978 Jun; 31:567-577.
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Tontini GE, Vecchi M, Pastorelli L, Neurath MF, Neumann H.Differential diagnosis in inflammatory bowel disease colitis: state of the art and future perspectives.World J Gastroenterol. 2015;21(1):21–46. doi:10.3748/wjg.v21.i1.21Venkateswaran N, Weismiller S, Clarke K.Indeterminate Colitis - Update on Treatment Options. J Inflamm Res. 2021 Nov 30;14:6383-6395. doi: 10.2147/JIR.S268262Thurgate LE, Lemberg DA, Day AS, Leach ST.An overview of inflammatory bowel disease unclassified in children.Inflamm Intest Dis. 2019;4(3):97-103. doi:10.1159/000501519Crohn’s and Colitis Foundation.Medication options for Crohn’s disease.Crohn’s and Colitis Foundation.J-pouch surgery.American Cancer Society.What is an ileostomy?Additional ReadingGuindi M, Riddell RH. “Indeterminate colitis.“J Clin Pathol. 2004 Dec; 57: 1233–1244.Odze R. “Diagnostic problems and advances in inflammatory bowel disease.“Mod Pathol. 2003 Apr;16:347-358.Pezim ME, Pemberton JH, Beart RW Jr, et al. “Outcome of “indeterminant” colitis following ileal pouch-anal anastomosis.“Dis Colon Rectum. 1989 Aug; 32:653-658.Price AB. “Overlap in the spectrum of non-specific inflammatory bowel disease–‘colitis indeterminate’.“J Clin Pathol. 1978 Jun; 31:567-577.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Tontini GE, Vecchi M, Pastorelli L, Neurath MF, Neumann H.Differential diagnosis in inflammatory bowel disease colitis: state of the art and future perspectives.World J Gastroenterol. 2015;21(1):21–46. doi:10.3748/wjg.v21.i1.21Venkateswaran N, Weismiller S, Clarke K.Indeterminate Colitis - Update on Treatment Options. J Inflamm Res. 2021 Nov 30;14:6383-6395. doi: 10.2147/JIR.S268262Thurgate LE, Lemberg DA, Day AS, Leach ST.An overview of inflammatory bowel disease unclassified in children.Inflamm Intest Dis. 2019;4(3):97-103. doi:10.1159/000501519Crohn’s and Colitis Foundation.Medication options for Crohn’s disease.Crohn’s and Colitis Foundation.J-pouch surgery.American Cancer Society.What is an ileostomy?
Tontini GE, Vecchi M, Pastorelli L, Neurath MF, Neumann H.Differential diagnosis in inflammatory bowel disease colitis: state of the art and future perspectives.World J Gastroenterol. 2015;21(1):21–46. doi:10.3748/wjg.v21.i1.21
Venkateswaran N, Weismiller S, Clarke K.Indeterminate Colitis - Update on Treatment Options. J Inflamm Res. 2021 Nov 30;14:6383-6395. doi: 10.2147/JIR.S268262
Thurgate LE, Lemberg DA, Day AS, Leach ST.An overview of inflammatory bowel disease unclassified in children.Inflamm Intest Dis. 2019;4(3):97-103. doi:10.1159/000501519
Crohn’s and Colitis Foundation.Medication options for Crohn’s disease.
Crohn’s and Colitis Foundation.J-pouch surgery.
American Cancer Society.What is an ileostomy?
Guindi M, Riddell RH. “Indeterminate colitis.“J Clin Pathol. 2004 Dec; 57: 1233–1244.Odze R. “Diagnostic problems and advances in inflammatory bowel disease.“Mod Pathol. 2003 Apr;16:347-358.Pezim ME, Pemberton JH, Beart RW Jr, et al. “Outcome of “indeterminant” colitis following ileal pouch-anal anastomosis.“Dis Colon Rectum. 1989 Aug; 32:653-658.Price AB. “Overlap in the spectrum of non-specific inflammatory bowel disease–‘colitis indeterminate’.“J Clin Pathol. 1978 Jun; 31:567-577.
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