IBS

Irritable Bowel Syndrome (IBS)

IBS is one of the most common functional disorders seen in gastroenterological practice.
It is characterized by abdominal pain/discomfort associated with bowel habit disturbances, bloating, and other symptoms usually defined as unrelated to any organic abnormality.

Diagnosis of irritable bowel syndrome:
IBS investigators have identified a set of symptoms that provide physicians with guidelines toward a diagnosis of IBS. These are called the Rome Criteria.

The Rome criteria:

1. Continuous or recurrent symptoms of abdominal pain or discomfort that
A) may be relieved with defecation,
B) may be associated with a change in frequency, or
C) May be associated with a change in the consistency of stools.

2. Two or more of the following are present at least 25 percent of the time:
A) Altered stool frequency (greater than 3 bowel movement per day or less than 3 bowel movements per week)
B) Altered stool form (hard or loose watery stools or poorly formed stools)
C) Passage of mucous stools
D) Bloating (feeling of abdominal distention)

Many patients experience other symptoms that are consistent with irritable bowel syndrome. However, the Rome criteria do assist researchers and clinicians by correlating and describing symptoms uniformly.

Other important factors are the presence or absence of pain at night, gastrointestinal bleeding, fevers, chills, sweats, weight loss, etc. The presence of these types of symptoms suggest alternative diagnoses. These complaints do not exclude an underlying diagnosis of irritable bowel syndrome but suggest other diagnoses that may have other treatments. Thus, IBS may be coexistent with other acute or chronic gastrointestinal illnesses.

Lab diagnosis (for physicians, students):

patients with IBS have an increased number of inflammatory cells in the ileum and colorectum. These inflammatory cells have been documented to be closely apposed to nerves supplying the intestinal mucosa and to release a wide array of inflammatory mediators, thus providing a morphological basis for the hypothesis that inflammation may perturb gut sensorimotor function.
The cause of the low-grade intestinal inflammatory response is as yet unknown and may involve a number of factors, including, for example, undiagnosed food allergies, changes in bacterial microflora, genetic factors (polymorphism leading to decreased anti-inflammatory cytokine synthesis), or bile acid malabsorption.
A peculiar form of IBS has been related to a previous episode of acute gastroenteritis (i.e., postinfectious IBS).

Also see: immune-mediated enteric neuropathy for info of enteric nervous system involvement in IBS