The chimp's swollen butt

Here's a folk tale I posted about how the chimpazee's bottom became swollen and red. It's a story translated from Yoruba and provided a challenge in writing about fecal matter without sounding disgusting. The Yoruba version never seemed that way whenever the lion shouted "Su dundun", but how do you translate that into English? I had run into a similar situation with the folk tale of the three brothers and the pot of porridge but I did not hesitate in replacing any unpleasantness with stones. I couldn't perform a similar replacement here without losing the main elements of the story, so after testing alternate words and several hesitations, I thought "let's just do it".

But I wonder if I'm thinking way too much about this.