|A micrograph demonstrating cryptitis, a microscopic correlate of colitis. H&E stain.|
In a medical context, the label colitis (without qualification) is used if:
Common symptoms of colitis may include: mild to severe abdominal pains and tenderness (depending on the stage of the disease), persistent hemorrhagic diarrhea with pus either present or absent in the stools, fecal incontinence, flatulence, fatigue, loss of appetite and unexplained weight loss.
Symptoms suggestive of colitis are worked-up by obtaining the medical history, a physical examination and laboratory tests (CBC, electrolytes, stool culture and sensitivity, stool ova and parasites et cetera). Additional tests may include medical imaging (e.g. abdominal computed tomography, abdominal X-rays) and an examination with a camera inserted into the rectum (sigmoidoscopy, colonoscopy).
An important investigation in the assessment of colitis is biopsy. A very small piece of tissue (usually about 2mm) is removed from the bowel mucosa during endoscopy and examined under the microscope by a histopathologist. It can provide important information regarding the cause of the disease and the extent of bowel damage.
There are many types of colitis. They are usually classified by the cause.
Types of colitis include:
A subtype of infectious colitis is Clostridium difficile colitis, which is informally abbreviated as "C-diff colitis". It classically forms pseudomembranes and is often referred to as pseudomembranous colitis, which is its (nonspecific) histomorphologic description.
Enterohemorrhagic colitis may be caused by Shiga toxin in Shigella dysenteriae or Shigatoxigenic group of Escherichia coli (STEC), which includes serotype O157:H7 and other enterohemorrhagic E. coli.
Indeterminate colitis is the classification for colitis that has features of both Crohn's disease and ulcerative colitis. Indeterminate colitis' behaviour is usually closer to ulcerative colitis than Crohn's disease.
Atypical colitis is a phrase that is occasionally used by physicians for a colitis that does not conform to criteria for accepted types of colitis. It is not an accepted diagnosis per se and, as such, a colitis that cannot be definitively classified.
Some people may be admitted into the hospital following the colonoscopy depending on results. It is sometimes necessary to get the patient started on a steroid to speed up the healing of the colon. It may also be necessary to get the patient hydrated from the fluid loss and iron replaced from the loss of blood. After a hospital stay, the patient may be put on a daily medication to manage their chronic colitis. The medication can be an anti-inflammatory or an immunosuppressant. There are many different types of medication used and the doctor will prescribe the one they see fit. If the patient doesn't respond, new medications will be tried until there is a good fit.
Moreover, several studies recently have found significant relationship between colitis and dairy allergy (including: cow milk, cow milk UHT and casein), suggesting some patients may benefit from an elimination diet.
In the lab, the CRISPR-Cas systems effectively killed C. difficile bacteria. Researchers tested this approach in mice infected with C. difficile. Two days after the CRISPR treatment, the mice showed reduced C. difficile levels. Next steps include retooling the phage to prevent C. difficile from returning after the initial effective killing.