Irritable bowel syndrome

What it is

The Rome IV criteria define it as recurrent abdominal pain at least 1 day per week for the past 3 months, with two or more of: 1) pain related to defecation; 2) a change in stool frequency; 3) a change in stool form. Pain brought on by eating, and increased gas and bloating, are observed in the condition but are not part of that count. Weight loss and waking at night to defecate are not typical of it at all. Other symptoms are urgency, straining, a feeling of incomplete evacuation and passing mucus. It is subtyped by the predominant stool pattern: with constipation, with diarrhea, or mixed. The criteria must be fulfilled for the last three months with symptom onset at least six months before diagnosis. The subtypes are read off the Bristol stool form scale: IBS with constipation is type 1 and 2, IBS with diarrhea is type 6 and 7, mixed IBS is both, and unspecified IBS meets the diagnostic criteria but cannot be accurately categorized into one of the other three subtypes. The pain itself settles with defecation.