Differential Diagnosis
Symptoms
The primary symptoms of IBS are abdominal pain or discomfort in association with frequent diarrhea or constipation, a change in bowel habits. There may also be urgency for bowel movements, a feeling of incomplete evacuation (tenesmus), bloating or abdominal distention. People with IBS more commonly than others have gastroesophageal reflux, symptoms relating to the genitourinary system, psychological symptoms, fibromyalgia, chronic fatigue syndrome, headache and backache.
Rome Process for Diagnosing IBS
The cardinal requirement for the diagnosis of IBS is abdominal pain. The Rome II criteria is used to diagnose IBS after a careful examination of the patient's medical history and physical abdominal examination which looks for any 'red flag' symptoms. More recently, the Rome III criteria, incorporating some changes over the previous set of criteria, have been issued. The Rome II and III efforts have integrated pediatric contents to their set of criteria.
According to the Rome II committees and the Functional Brain Gut Research Group, IBS can be diagnosed based on at least 12 weeks, which need not be consecutive, of the preceding 12 months there was abdominal discomfort or pain that had two out of three of these features:
Relieved with defecation; and/or
Onset associated with a change in frequency of stool; and/or
Onset associated with a change in form (appearance) of stool.
Symptoms that cumulatively support the diagnosis of IBS:
Abnormal stool frequency (for research purposes, "abnormal" may be defined as greater than 3 bowel movements per day and less than 3 bowel movements per week);
Abnormal stool form (lumpy/hard or loose/watery stool);
Abnormal stool passage (straining, urgency, or feeling of incomplete evacuation);
Bloating or feeling of abdominal distention.
Supportive symptoms of IBS:
A) Fewer than three bowel movements a week
B) More than three bowel movements a day
C) Hard or lumpy stools
D) Loose (mushy) or watery stools
E) Straining during a bowel movement
F) Urgency (having to rush to have a bowel movement)
G) Feeling of incomplete bowel movement
H) Passing mucus (white material) during a bowel movement
I) Abdominal fullness, bloating, or swelling
Diarrhea-predominant: At least 1 of B, D, F and none of A, C, E; or at least 2 of B, D, F and one of A or E.
Constipation-predominant: At least 1 of A, C, E and none of B, D, F; or at least 2 of A, C, E and one of B, D, F.
Red flag symptoms which are not typical of IBS:
Pain that awakens/interferes with sleep
Diarrhea that awakens/interferes with sleep
Blood in the stool (visible or occult)
Weight loss
Fever
Abnormal physical examination