Sounds like you may have introduced some bacterium to the lower digestive tract which has gotten a chance to gain a foothold there.
Were your probiotics used orally? It takes /really/ high-concentration probiotics to get them all the way through from the mouth to the end of the line. That is why some folk use probiotic enemas to change the bacterial population in the colon.
I'm sorry to hear about the difficulty that has happened to you. Please make sure to have condoms around your bedside whenever you choose to play anally! Even if it is fingers, make sure you are washed thoroughly both before and after.
Some methods you can try for the bad rectal smell:
Non-sweetened yogurt whey (drain 1 liter yogurt overnight through a coffee-filter in a funnel- collect the drained off water, that is the whey.) in a low enema, retained for 15-30 minutes (very small portions of water)
Kombucha tea in an enema
Probiotics dissolved in enema water
Butyric Acid, 1-2 drops in 1 liter enema water (reduces unhealthy flora while nourishing the good)
If you are new to colonics/enemas, definately do some reading, and be gentle with yourself. A salt water flush (oral) may be best before you use ANY enemas, to avoid carrying the bacterium higher in your digestive tract.
Be aware that enema treatment is something that requires a cycle of usage to be effective- one time solutions are very rare.
Having constipation is a sign of needing especially butyric acid - it is a byproduct of healthy gut flora. It causes the gut wall to produce mucous and to move material along- it prevents constipation basically by lubricating, maintaining and /feeding/ the gut wall (it prefers butyrate to glucose). It also prevents certain types of gut flora (bacteria, yeasts, etc) from becoming dominant in the digestive tract and creating issues like you list- bloating, constipation and gas.
Butyrate is found in whey, kombucha tea, and any other fermented food. It is available cheaply as fishing lure drops (I got mine on ebay), a bit more expensively as sodium butyrate capsules, and..
Absolutely best of all, in -live- apple cider vinegar (like Bragg's brand.) What you want is both the probiotics and the acids they produce (of which butyric acid is only one).
And yes, butyrate stinks too. Just.. not permanently. ;-)