The doctor took an extra moment to check the instruments he had brought from the hospital in his bag. Some of the procedures he would have to perform were particularly invasive for a girl of Sofia's age, and he knew that if he explained this to her in advance, Sofia would get upset, or worse, refuse.

He couldn't afford that, he had to proceed step by step without letting her get away.

The doctor stood up and took two Velcro straps from the bedside rails. He slid them on with a confident gesture, and the sharp sound of the adhesive opening made Sofia jump.

"W-what are those?" she stammered.

"Just a safety precaution," he replied in a professional tone. "You're not used to such thorough examinations. You might move involuntarily and hurt yourself. This way you'll be more relaxed, and I'll be able to work better."

Before she could really protest, he wrapped the straps around her knees and secured them to the supports. Sofia felt immobilized, trapped in a position that exposed her more than she had ever imagined.

"It's not necessary... I can stay still," she whispered, but she already knew that her objections would be futile.

"I assure you it's better this way," concluded the doctor, meeting her gaze firmly.

And in that moment, as embarrassment and fear overwhelmed her, Sofia felt another sensation growing beneath her skin: an insistent, uncontrollable heat. Being pinned down, so exposed, with no chance of moving, made her feel submissive and at the same time incredibly aroused. With dismay and shame, she realized that her body was reacting exactly as it had to the enema.

The doctor put on a new pair of sterile gloves and calmly prepared the equipment on the tray: a catheter set, sterile saline solution, a syringe for the retention balloon, and disinfectant. Everything had to be done by the book, because the goal was to obtain a sterile urine sample for diagnosis.

Sofia, meanwhile, watched him with growing apprehension. She recognized some familiar instruments on the tray: the thin cannulas the doctor had used days earlier to improvise the enema and those syringes. Just seeing them made her shudder. The memory of that first experience came back vividly, along with the conflicting feelings of embarrassment and excitement she had felt. Now, however, she understood that it would not be the same thing: the procedure seemed more complex, more 'serious'.

"Now Sofia will disinfect the area, you will feel a little discomfort," he announced in a low tone, without adding anything else. He didn't want to alarm her by explaining the procedure in detail: it would have been worse.

After dipping a long swab in the antiseptic, she approached her legs, which were fixed to the supports. With precise movements, she began to clean the periurethral area: first the edges, then the innermost mucosa. Sofia immediately flinched.

"Ahh... it burns!" she moaned, clenching her hands against the sheet on the bed.

"It's normal, it means the disinfectant is working," he reassured her, continuing carefully.

Once the external area had been disinfected, he gently inserted the swab a few centimetres into the urethral orifice, rotating it slowly. The sensation was new to her, but almost intolerable!

"OW... STOP, PLEASE! What are you doing?"

She tried in vain to resist, but the discomfort caused by the swab inside her already inflamed urethra was truly unbearable.

Fortunately for her, the torture did not last long, but the doctor knew that the next procedure would be difficult for Sofia to stomach.

The doctor took the sterile catheter out of its packaging and generously sprinkled it with disinfectant and lubricant—an extra step to ensure that the procedure was as safe and painless as possible. Then, with precision, he brought it close to the prepared urethra.

"Now you'll feel a little discomfort, try not to move..." he said in a firm voice.

He paused for a moment to look at the girl so exposed, completely open in front of him, then — with slow and steady pressure — he placed the tip of the catheter against the orifice and began to insert the thin tube. Sofia immediately held her breath, her face contorted. After a few millimetres, she began to moan, her voice broken by soft groans that became increasingly insistent.

"Doctor, stop... please..." she murmured, almost crying.

"Hang in there, it won't take long," he reassured her, continuing his advance with controlled calm.

The catheter slid inside, centimetre by centimetre, until it reached the necessary depth. Sofia shuddered, instinctively clenching her thighs against the straps that prevented her from closing them completely. When the cannula was in place, the doctor connected the syringe and quickly inflated the small retention balloon. She immediately felt a new weight, a dull, constant pressure inside her bladder, enough to make her gasp.

"There, that's it," he finally said, carefully checking that the connection was secure. He temporarily closed the catheter with a small metal clamp, then placed a sterile test tube between Sofia's open legs. With a decisive gesture, he released the clamp: the urine began to flow slowly, a clear, continuous stream that collected neatly in the sterile container.

Sofia turned her head toward the clinic window, her face flushed to the ears. The sense of exposure was overwhelming: she felt subdued, unable to oppose a procedure so intimate and invasive. Yet, against all logic, alongside the burning and the embarrassment another warmth was growing within her—deeper, more confusing—blurring her emotions and leaving her with a turmoil she found hard to hide.

The doctor did not remove the catheter. On the contrary, he left it firmly in place, ready for the next stage. He took a 200 ml syringe from the trolley. Sofia, with a sudden shiver, immediately recognized that size. It was identical to the one he had used for the enemas, and the memory made her even more excited.

Calmly, he filled it with a physiological solution mixed with a specific disinfectant, diluted to 2%. He connected it to the catheter connector and began to slowly push the syringe plunger. "Now you'll feel a little internal pressure... it's normal, try to breathe slowly," he explained in a matter-of-fact tone. Sofia's bladder began to swell, the sensation was unusual and immediately uncomfortable.

"AARGHHH"

A stifled scream rose in her throat as the liquid entered.

"Ah... no, it's too much... it burns, what is it?..." she protested, moving her pelvis slightly, but forced to remain still by the supports holding her in place.

"Don't worry, hang in there, it's to disinfect the bladder properly, we'll just do one more and that's it... it'll be over soon," he replied, checking the progress of the liquid.

Once the first instillation was complete, he disconnected the syringe and immediately prepared a second one.

He knew that the bladder of a girl Sofia's age could hold at most half a liter of urine and that the second syringe would most likely cause the young girl considerable discomfort.

In fact, the break was short for the poor girl.

The operation was repeated under Sofia's frightened gaze. The liquid slowly entered her already tense bladder, amplifying the feeling of swelling and the urge to urinate.

"MMMM... Doctor, please, the urge is too strong. Stop!"

The girl's moans grew louder as the amount of liquid increased, her hands clenched on either side of the bed, her legs almost trembling. When all the liquid had been inserted, Sofia was at the limit of her endurance, the urge was very strong, and the catheter prevented her from relieving herself.

Finally, after closing the catheter, the doctor, accustomed to patients' protests, connected a drainage bag and, after a few moments, opened the catheter: the fluid mixed with urine began to flow continuously.

She instinctively looked down, but the sight of the bag filling up struck her with a wave of shame. She was no longer in control, it was the doctor who allowed, observed, and even recorded this act, which until then had remained an intimate, hidden fact.

When her bladder was completely empty, the doctor stared at the bag and checked that the drainage was regular. Sofia, on the other hand, remained motionless, exhausted.