Like the users of other social networks, Instagramers have to deal with their fair share of spam and online-abuse. Fortunately, you've had the ability to block specific words from your comments for a while, but today Instagram has introduced a number of additional features, all of which will become available in the coming weeks, that should help make your account and Instagram as a whole a more pleasant place.
When posting a new image you can now disable commenting for the image in the new advanced settings menu. There is not yet an option for a global shutdown of commenting for your account, though. The ability to 'heart' a comment for it to encourage positive comments from others is a less drastic approach but likely less efficient as well.
There is also a new feature for users with private accounts. Previously, you had to block contacts if you changed your mind about them seeing your images. Now you have the option to quietly remove them from your followers list, which they won't be notified about.
Finally, there is a new function to alert Instagram about what it refers to as 'self-injury' posts. You can flag images if you are worried about the well-being of a users and a dedicated team at Instagram will then contact them and put them in touch with organizations that offer help. As a package these new features should help reduce spam and other unpleasant commenting on Instagram, as long as you put the time in and use them.