The investigators will use Culturelle®, a probiotic composed of the micro-organisms Lactobacillus GG. This formulation has been used for the treatment of gastrointestinal inflammation in numerous clinical trials. Dosing will follow the manufacturer's recommendation for children (1 capsule/packet per day), and will be monitored by Dr. Patrick Seed from the department of pediatrics. Weekly side effects and clinical changes will be monitored by both study therapist and caregiver using the Children's Global Assessment Scale and the Clinical Global Impression Scale (Severity, Improvement, and Efficacy). The intervention duration is 30 days.

The investigators will use Culturelle®, a probiotic composed of the micro-organisms Lactobacillus GG. This formulation has been used for the treatment of gastrointestinal inflammation in numerous clinical trials. Dosing will follow the manufacturer's recommendation for children (1 capsule/packet per day), and will be monitored by the study Co-PI, Dr. Seed. Weekly side effects and clinical changes will be monitored by both study therapist and caregiver using the Children's Global Assessment Scale and the Clinical Global Impression Scale (Severity, Improvement, and Efficacy). The treatment duration is 30 days.

Child and parent report is used to obtain ratings of pain intensity on a 0-12 scale. A lower score equates to lower pain intensity. Ratings are obtained for a one-week period pre and post intervention, and measured 3 times daily. Pre-treatment assessments took place days 1-7, participants were treated days 8-36, and post-intervention assessments were completed days 37-44. All time points will be averaged and combined across raters (child and parent) resulting in an average pain severity rating pre and post-treatment. The change in this average rating will be assessed as pain severity outcome. This measure was averaged with the pain frequency average score (see Primary Outcome 2) to result in one primary severity/frequency pain rating pre and post treatment. The change in this combined measure is our primary index of change.

Child and parent report is used to obtain ratings of pain frequency, the number of distinct occasions that pain was reported. Frequency was obtained for a one-week period pre and post intervention, and measured 3 times daily during these intervals. During the 30-day intervention, end of day frequencies were made. Pre-treatment assessments took place days 1-7, participants were treated days 8-36, and post-intervention assessments were completed days 37-44. The average number of episodes across these time points will be calculated pre and post treatment. The change in this average frequency from pre to post treatment will be the measure of change.

We report the change in magnitude of self-reported state anxiety derived from summed raw scores obtained through the six-item short-form of the state scale of the Spielberger State-Trait Anxiety Inventory at baseline and 30 days from baseline. Scores in the scale range from 6-24, with greater scores indicating worse anxiety. We obtained the summed raw scores after reverse scoring items 1, 4 & 5.

Adherence was calculated as: ("the days probiotic was taken"/"total number of days of treatment") x 100, with results ranging from 0% (no probiotics taken at all) to 100% (probiotics taken 30 days out of the 30 day-treatment period). Researcher will subtract the number of pills/packets taken from the total amount.

The investigators will use Culturelle®, a probiotic composed of the micro-organisms Lactobacillus GG. Dosing will follow the manufacturer's recommendation for children (1 capsule/packet per day), and will be monitored by Dr. Patrick Seed from the department of pediatrics. The intervention duration is 30 days.

Child and parent report is used to obtain ratings of pain intensity on a 0-12 scale. A lower score equates to lower pain intensity. Ratings are obtained for a one-week period pre and post intervention, and measured 3 times daily. Pre-treatment assessments took place days 1-7, participants were treated days 8-36, and post-intervention assessments were completed days 37-44. All time points will be averaged and combined across raters (child and parent) resulting in an average pain severity rating pre and post-treatment. The change in this average rating will be assessed as pain severity outcome. This measure was averaged with the pain frequency average score (see Primary Outcome 2) to result in one primary severity/frequency pain rating pre and post treatment. The change in this combined measure is our primary index of change.

Data was missing for one participant

The investigators will use Culturelle®, a probiotic composed of the micro-organisms Lactobacillus GG. Dosing will follow the manufacturer's recommendation for children (1 capsule/packet per day), and will be monitored by Dr. Patrick Seed from the department of pediatrics. The intervention duration is 30 days.