That is always an option as well Lol. Weirdly though I've never been hurt by the enemies I've nommed. Just watched their struggles and (very rarely) escape from the stomach. Another reason why it felt as if the debuff skill was quite lacking.
Whenever you get the flavour text of the enemy struggling, you'll see how your health has decreased ever so slightly. That makes the skill do more against enemies with maybe more health or is more likely to escape over all.
Also, it deals more damage than just digesting or using Belly Rub if I remember correctly so that's always a plus, and also the reason (I think) it uses less tp :)