Diarrhea and bowel disturbance: Nearing labor your body will produce prostaglandins, a chemical which will cause loose bowel movements. A very unpleasant sign of impending labor, but one which does let you know the baby is coming soon. If you have been suffering from constipation, this may be a bit of a relief.
As a cool-weather vegetable, brussel sprouts do well when the plants are well-watered, especially during the hot summer months when they are first transplanted (for a fall harvest), or are reaching maturity (during an early spring planting).
If your Brussels sprouts are opening, your soil may be too loose and infertile. This plant likes heavy soil, even on the tight side. It's best to mix in lots of well-rotted compost in autumn to give the soil time to settle and firm up. The other reason sprouts can open up: the weather got too warm.