Oh that's sooo funny reminds me of my grandmother who swore if her quick march up and down the garden path didn't work(get her bowels working) she would use some soap, hope to never need the matchstick or the soap.
Could be a black fly bite. Mine get red welts on them if they get bit by them. Tucker has really bad reactions to mosquito bites, they puff up and blister so I have to really watch him and make sure I put his bug spray on him.
She now did this after getting up from a loong long 2 or 3 hr nap , after doing her downward dog and cat stretch , stretching down then back into a normal position she whined and turned to her left hind side , muscle cramp ?, stifle stuck?, is really weird I've squeezed every place it might be and nothing , she does go into a sit when I'm around her back end and squeeze her back end ? Could that be an issue ??