Irritable bowel syndrome: Diagnosis and pathogenesis

Table 1 Rome III criteria for the diagnosis of irritable bowel syndrome¹

Recurrent abdominal pain or discomfort with onset at least 6 mo prior to diagnosis, associated with 2 or more of the following, at least 3 d/mo in the last 3 mo

Improvement with defecation

Onset associated with change in frequency of stool

Onset associated with change in form (appearance) of stool

Symptoms that cumulatively support the diagnosis are:

Abnormal stool frequency (greater than 3 bowel movements per day or less than 3 bowels movements per week)

Abnormal stool form (lump/hard or loose/watery stool)

Abnormal stool passage (straining, urgency or feeling of incomplete evacuation)

Passage of mucous

Bloating or feeling of abdominal distension

¹Adapted from reference [1] with the permission from Nova Science Publisher, Inc.

Table 2 Subtyping of irritable bowel syndrome¹

IBS with constipation-hard or lumpy stools > 25% and loos or watery stools < 25% of bowel movements

IBS with diarrhea-loos or watery stools > 25% and hard or lumpy stools stools < 25% of bowel movements

Mixed IBS-loos or watery stools > 25% and hard or lumpy stools stools > 25% of bowel movements

Unsubtyped IBS-insufficient abnormality of stool consistency to meet criteria for IBS-C,D or M

¹Adapted from reference [1] with the permission from Nova Science Publisher, Inc. IBS: Irritable bowel syndrome; IBS-C: IBS with constipation; IBS-D: IBS with diarrhea-loos; IBS-M: IBS with a mixture of both diarrhoea and constipation.