Mako visits the hospital due to having had no bowel movement for three days, experiencing abdominal bloating during class. Under the supervision of Director Higashimoto, rookie female doctor Dr. Kagami begins examining Mako. The examination starts by removing Mako's skirt, laying her flat on her back on the bed, and massaging her lower abdomen. Strong pressure on the colon activates intestinal movement, producing audible gurgling sounds. Next, Mako is placed in a quadruped position for anal massage. Dr. Kagami helps Mako relax, applying vaseline and gently stroking the anal folds with her finger, causing sweet moans to escape Mako's lips. As the finger slowly moves back and forth, Mako's breathing grows heavier. When the finger penetrates and stimulates inside the rectum, her bladder is triggered and she involuntarily urinates. After confirming rectal activity, Mako remains on all fours, panting. Each time she tenses, her anus swells and rolls outward. When she strains her lower abdomen, she loses bladder control again. Amid repeated dilation and contraction of her anus, a brown mass gradually appears. Hard, small fecal pieces drop out in succession onto the absorbent sheet. Due to urinary incontinence during anal massage, a urinary catheter is inserted to check for bladder abnormalities. The catheter tip reaches the bladder, and dark yellow urine drips into a glass container. Next, the experienced Director performs a rectal examination. Mako is made to hug her knees in lithotomy position, exposing her small, bud-like anus. When the man's thick finger penetrates her anus, sexual pleasure arises in Mako, and she emits sweet, sensual moans. To further dilate the anus, a second finger is added, intensifying Mako's moaning as her anal sphincter tightly grips the fingers. The doctor adjusts his finger movements to match Mako's sensual responses, increasing speed. At the peak of her ecstasy, urine gushes out like a fountain, and white vaginal fluid leaks out, pooling in the doctor's palm. Then, anal dilators (bougies) are used progressively to stretch the anus and test sensitivity. Starting with a thin bougie finer than a pinky, they switch to thicker ones wider than a thumb, stimulating Mako's anus. To check for remaining feces, an anoscope is inserted, revealing residual fecal matter deep in the rectum. Dr. Kagami recommends enema-based colon cleansing. A special enema device with a thick nozzle is used, adjusting the height of the irrigator so lukewarm water flows back and forth between the irrigator and rectum. Five hundred cc of lukewarm water flows into Mako's rectum, then drains back by lowering the irrigator's position. As the process repeats, the water gradually turns brown. To delay defecation, Mako is fitted with a diaper, but she immediately releases loud gurgling sounds, discharging a brown-tinted liquid. The white diaper becomes stained with brown fluid. In the final stage, 1000 cc of lukewarm water is administered via enema, forcing repeated evacuations to cleanse the intestines. The volume exceeds Mako's physical limits, causing brown, cloudy liquid to backflow into the irrigator. Mako's endurance reaches its breaking point; the moment the anal nozzle is removed, her anus ruptures open and turbid fluid erupts forcefully.