One of the most unfortunate things about Bile Spewers is that, regardless of the defense on your armor (Light, Medium, or Heavy), they can one-shot you with their bile attack if you get hit directly. Bile Spewers are actually the reason I started exclusively using Light Armor, which gives you extra speed and stamina at the cost of durability, since a direct hit from their bile attack will kill you even in the heaviest armor (with a defense of 144).
Because of this, it’s important to walk left or right to strafe the attack as you return fire. In the mid-to-long-range, this will ensure you avoid their attack entirely. If you’re close, it will ensure you only take a little bit of damage and not the full brunt of it.
Their weak point is their head, so make sure to really lay into them with whatever weapon you use, but the Breaker automatic shotgun makes very quick work of them if you must fight up close. If you’re taking support weapons, the Grenade Launcher is also a fantastic way to take them out at range, and it has the bonus of blowing up smaller bugs that tend to gather around them.
If you’re defending a location, Sentries will do a lot of work to clear them out before they become a problem, but this is a great strategy for every enemy, not just Bile Spewers. Bring a Mortar Sentry–one of the best Stratagems in Helldivers 2–with you and place it in a high location, where enemies won’t be able to get to it easily, then keep moving to have the best chance for survival. You can also bring a Guard Dog Rover along as your backpack item and stay mobile as it deals damage. Every little bit helps.
Keep these tips in mind and you’ll be putting those Bile Spewers in the ground, instead of the other way around. Happy hunting, Helldivers!