After washing his hands, Doctor Keiran snapped on latex gloves and then pulled the tourniquet tightly around Callie's left arm. He then began palpating her median cubital vein in the centre of her arm. When the vein sprang back under his fingers he quickly wiped the area with alcohol and picked up the butterfly needle.

"Just relax Callie. Sharp scratch now...."

Callie held her breath, turned her face away and waited for the quick sharp pain that signalled that the needle was in. None came. Instead there was a very subtle dull ache as her vein was penetrated and the doctor filled several blood culture bottles before gently removing the needle.

"Don't look so worried" the doctor said, pressing a small circular plaster into the crook of her elbow in a way that intensified the tender ache in her wounded vein "I don't bite, I promise."

Callie had been the one to take control of her situation. She had paid a lot of money for the sexual pleasure retreat and she really wanted the examination to happen.

At home she had courage and determination but now she was here, semi naked and waiting for the doctor - who was incredibly attractive - to touch and explore her in very intimate ways, it felt unbearably scary and intimidating.

Still, as nervous as Callie felt, she wanted answers. Sex should be fun and fulfilling. It should bring people closer together not drive relationships apart. If there was a sexual or hormonal problem, she wanted the doctor to find it and fix it.

"I'm sorry doctor. It's just I'm very nervous."

"I can see that. We will go slowly Callie. I will talk you through everything I'm going to do before I do it. First, it's just a brief examination, it's nothing too intense so you can relax. You can stay where you are for now"

Callie sat on the exam couch, her feet were just skimming the floor. The gown she was wearing was short and only just covered her upper thighs. It was also thin, almost see-through even, as well as baggy and very low cut.

Most ominously of all, Callie noticed that there were tie fastenings down one side. Presumably the ties were for easy exposure of either her front, or... Callie swallowed hard.. her bottom. Even though she had been allowed to keep her panties on, the gown, and especially her lack of a bra made her feel very exposed and vulnerable.

First of all, doctor Michaels used an opthalmic torch to look into Callie's eyes. Very carefully, he retracted her eye lids and aimed the light deeply into the back of her eye. To Callie, Dr Keiran's evaluation seemed to take forever and she nervously held her breath as the doctor leaned in closer to her, his face serious and thoughtful as every structure and vessel was illuminated and he studied Callies reaction to the light.

Next he selected a different torch and looked into Callie's ears, the cool prong of the device rested into the opening of her ear whilst the doctor tugged gently on her lobe.

Satisfied with what he saw, he quickly moved on and Callie began to relax again. Now she felt his cool hands reaching around her neck and gently palpating at the back of her head, his fingers entwined within her hair. It felt good and Callie was just starting to enjoy his touch when he moved again, this time his hands began feeling around her jaw line and then down towards her throat.

"Just look to the left for me.... Good... and the right.... So... I don't see any thyroid swelling but we've done a full blood count and because thyroid levels can swing, I also like my participants to undergo regular rectal temperature readings that are helpful in giving me an idea of what your metabolism is doing"

"RECTAL temperature? In my bottom??"

Keiran shot her a look of amusement. Like many of his patients, he had expected that the rectal temperature readings would be a problem that they would need to overcome. It's why he always raised it on the first day so that patients could be gently awakened to the pleasurable sensation that anal stimulation could provide.

"Does it have to be rectal? I mean.. you can take it elsewhere can't you?"

"Rectal readings are the most accurate. I would like to take your temperature now and we will be taking further readings at some point during every treatment session but also if you can take your temperature as soon as you wake each morning and write it down for me, that would be great.."

A fresh supply of nerves overtook Callie. She hoped that there would be another way. Rectal temperatures every morning really didn't seem that pleasant!

"I've never had it taken that way. I don't really like to touch my bottom... Is it really necessary to take it that way?"

"It will be quick.. and you know I'm going to need to see and touch your bottom if your treatment is to be effective...."