Eaton SC, Mangel AW, Hollis KA, Ameen VZ, Hamm LR, Andrews EB, Williams RL, Cook SF. Symptoms of diarrhea-predominant or alternating IBS: an exploratory analysis. Poster presented at the 20th ICPE International Conference on Pharmacoepidemiology & Therapeutic Risk Management; August 22, 2004. Bordeaux.

BACKGROUND: Irritable bowel syndrome (IBS) is characterized by a constellation of symptoms predominantly affecting the gastrointestinal tract. An understanding of the burden of illness is fundamental to making an assessment of the risk-benefit relationship for existing therapies, as well as for agents in development. Objective: The objective was to explore symptom severity of diarrheapredominant (dIBS) or alternating IBS (aIBS), using data collected by a novel web-based survey.

METHODS: A sample of 31,829 individuals was drawn from an online, web-based research panel (surveyed December 2001 to February 2002) consisting of over 150,000 household members. Probability sampling techniques and stratified, random-digit dialing were used to recruit the sample. Panel members received a screener for symptoms of IBS using Rome II criteria. For participants satisfying the Rome II criteria for either dIBS or aIBS, a second questionnaire addressing demographics, resource utilization, and symptoms was administered. Key measures included prevalence, demographic characteristics, health care utilization, and quality of life (SF-36). Five groupings of symptom severity were explored: 1. At least moderate abdominal pain, cramping, or discomfort in combination with diarrhea in the most recent episode and having IBS for ≥1 year 2. Urgency reported as often or always in the most recent episode and having IBS for ≥1 year 3. Pain scored as severe in the most recent episode and having IBS for ≥1 year 4. Urgency scored as often or always and pain as severe in the most recent episode 5. #4 and having IBS for ≥1 year.

RESULTS: The Rome II criteria for IBS were fulfilled for 1,713 participants, yielding a prevalence rate of 6.6% (CI: 6.3, 6.9). Of the 1,354 subjects subtyped as dIBS or aIBS, 1,180 completed the main questionnaire. Almost 70% of participants with dIBS and aIBS reported their most recent IBS episode within 3 months of the survey and 80% within 6 months. During this most recent episode, over 50% of participants had urgency present, 80% had loose or watery stool, and over 80% reported moderate or severe pain. Ten percent (10%) of participants had at least one of the symptom groupings.

CONCLUSIONS: This web-based method allows for collection of symptoms of episodic conditions such as IBS. The majority of dIBS and aIBS participants had a recent episode of IBS. These episodes are characterized by a substantial level of multiple symptoms. Ten percent had at least one combination of symptom severity groupings.