Wet Tail and Prolapse

Question
Hi. I sure hope you can shed some light on this situation for me. My daughter and I recently purchased a Teddy Bear Hamster at PetSmart (against my better judgement -I purchased a Guinea Pig 2 years ago & it got sick 2 days later and died) Anyhow, after 4 days with our hammie, he acquired diarrhea --I took him back to the store, and because we didn't want to "exchange" him for another, they took him over to Banfield (the "in-house" vet) They said he had wet-tail and prescribed him 10 days of anti-biotics and pedialite. We started the treatment this past Tuesday (4 days at this point) he's never really lost much energy --they think I caught it in time. I did notice during the treatment, his energy has lessened. He sleeps constantly --he comes out for an occasional run on his wheel ( a very slow run) some food and water. Tonight, I noticed a small ball-like thing around his anus. It's hard to tell what it is since there is hardened poo around it. I'm worried it's prolapse. How can I tell if it's prolapse? I can't seem to find a picture of it online for hamsters. I've been wiping his bottom area with warm-water gauze (vet reccomended) to assist in cleaning the poo-covered bottom and tail. Any suggestions on what to do? The vet is closed at this hour and I supppose it will be on Sunday. Please guide me as to where I can view a picture of what prolapse looks like on a hampster, if possible. I'm also worried that he's now constipated from the antibiotic. Could his anal hole be clogged? We just love this little guy. He's the friendliest hampster I've ever owned. He was friendly with us from day 1. I read somewhere online, that a bit of plain vanilla yogurt should be given twice a day with the antibiotics. Do you know of this to be true? I've read so many conflicting things online, I don't know who or what to believe. Your resources and feedback have been outstanding, so I'm trying this route now. Thank you for any advice or help you can give. Sorry for such a long message.

Answer
My newest female was from Petco, while inspecting her I found traces of wet tail. I ended up showing the woman in charge of small animals, so they put her on antibiotics before I was allowed to take her. I have no experience in the process of giving the antibiotics or in the recovery stages of wet tail since all of my other hamsters have been well cared for and never caught the disease.

Luckily I think what you may think is prolapse is actually a normal male hamsters testicles. They appear as a fleshy lump right on the hamster's bottom. I don't believe I have ever come across a picture of hamster rectal prolapse in my experience, but the hamster would be VERY uncomfortable, and I doubt he would have the strength to even run on his wheel. Oddly enough I can't find a good picture of a male hamster's testicles to show you, but they are usually flesh or pink colored, and are rounded in shape. I really believe this is most likely what the mystery lump is.