GI distress could be related to taking a new supplement. A probiotic supplement in particular can cause mild GI symptoms; however, symptoms usually subside within a week or two. If your symptoms continue for several weeks or if you are very uncomfortable, consider reducing the number of days per week that you take the supplement.
One option is to reduce the supplement frequency to every other day for two weeks, and then begin to take the supplement every day.
If you are sensitive to new supplements or feel more comfortable starting slowly, consider taking the probiotic two days a week for two weeks. For example, take the supplement on Monday and Thursday and then take it every other day for an additional two weeks. After that, you can try taking the supplement daily.