Apanasana
According to Health, this pose is a great way to "gain relief from bloating and gas pains."
How To: Lying flat on your back, hug your knees to your chest. Sway knees from side to side to maximize the stretch. Hold for several seconds. Repeat.
Cat Cow
Cat Cow is one of the several mobility, stretches, and strengthening exercises Miriam Fried, founder and head trainer of MF Strong, recommends to help keep your core strong.
How To: Start on all fours with your hands below your shoulders and your knees below your hips. Gently exhale and contract your abdominal muscles, pushing your spine upwards towards the ceiling. Hold for several seconds, head to falling towards your chest, maintaining alignment with the spine. Inhale and Let your stomach fall towards the floor (increasing the arch in your low back) and allow your shoulder blades to fall together (move towards the spine) and extend your gaze up. Hold for several seconds. Repeat.
Bird Dog
Fried also suggests trying Bird Dog for a flatter stomach, but no matter what you are targeting, Bird Dog is a good idea. According to Women's Health, "Bird Dog also puts tons of other muscles to work that allow you to stabilize while moving in this position, including the hamstrings, obliques, piriformis (a deep butt muscle that connects your sacrum to the top of your femur), pelvic floor muscles, serratus (muscles that wrap from the sides of your rib cage back around your shoulder blades), pecs, and triceps."
How To: Begin on all fours with your knees under your hips and your hands under your shoulders. Maintain a neutral spine by drawing your belly button to your spine and drawing your shoulder blades together. Inhale as you slowly raise your right arm and extend your left leg, keeping your shoulders and hips parallel to the floor. Pause at full extension and hold for several counts before returning to the start position. Repeat on the other side.
Dead Bug
Fried also recommends Dead Bug, which can help strengthen your core.
How To: Lie flat on your back, lifting your arms straight, directly over your shoulders. Lift your legs, positioning your knees over your hips, bending them slightly. Press your lower back into the floor, engaging your core. Inhale and slowly lower your left hand and right heel until they barely touch the floor. Exhale as you lift your hand and heel back to the original position. Repeat on the other side.