ANTI-COLIC BABY BOTTLE. Anti-Colic internal vent system is clinically proven to reduce colic. Decreases spit-up, burping and gas. CONSISTENT FLOW RATE. Vacuum-free feeding is closest to breastfeeding and Dr. Brown’s silicone nipples provide a consistent flow so babies can feed at their own pace. PRESERVES NUTRIENTS. The anti-colic vent system is proven