There are no definitive diagnostic criteria for CP. CP is a condition in which nonspecific inflammatory polyps develop mainly in the rectum and sigmoid colon, and the symptoms of CP are mucus secretion, diarrhea, bloody stools, and sometimes abdominal pain [2]. Blood tests often show hypoproteinemia, and the characteristic endoscopic findings of CP include multiple broad-based bulging lesions from the rectum to the sigmoid colon, with mucus attachment on the surface [2]. Pathological examination shows that the mucosal surface of the lesions is covered with inflammatory granulation tissue, which is called Cap [2]. The diagnosis of CP in Japan is based on the abovementioned characteristic symptoms and examination findings, which were used to diagnose CP in the present patient.
It has been theorized that the mechanism of CP may be mechanical stimulus or infection, but the definitive cause remains unknown [1, 2, 4]. There is currently no established treatment for CP, although various treatments have been used. 5-ASA is often ineffective in treating CP, while steroids cause temporary improvements followed by relapse [2, 5]. Although there are reports that MNZ is effective for CP [6], there are also reports that MNZ is ineffective [1, 2]; the response rate of MNZ is 28.6% [5]. Similarly, some reports that infliximab is effective in treating CP [7], while others report that it is ineffective [8]. In Japan, HP eradication has reportedly been successful in treating many cases of CP [2, 4]. In our case, various treatments such as MNZ, 5-ASA, steroids, and HP eradication therapy were not effective. Most of the previously reported cases of successful treatment of CP via HP eradication have involved patients with confirmed HP infection, and the relationship between HP infection and CP is drawing attention [2, 4]. However, there are reports of CP in patients who are HP-negative, as in our case [9]. The present patient underwent upper gastrointestinal endoscopy during his first visit to the local hospital and was HP-negative on rapid urease testing performed at that time. Even after CP was suspected, the fecal HP antigen and serum HP antibody titers were negative. Our patient did not have HP infection, which is probably why HP eradication treatment was ineffective. As our patient was resistant to medical treatment and had diarrhea, bloody stools, and abdominal pain, he was finally treated surgically.
The general indication for surgery for CP is resistance to medical treatment, and symptoms such as diarrhea and abdominal pain improve quickly after surgery. However, previous reports have shown that recurrence is not uncommon in patients who have undergone surgery, and the surgical procedure performed varies depending on the extent of the lesions [2, 2]. Gallegos et al. performed right hemicolectomy to treat recurrence in the right colon after left hemicolectomy [3]. In the present case, CP was found from the anal canal to the middle of the transverse colon, and anastomosis between the transverse colon and the anus was difficult because of the large distance. Therefore, we performed IPAA.
Our patient’s symptoms improved rapidly after resection. No recurrence of CP was observed in the ileal pouch, the stoma was closed about 3 months later, and no recurrence has been observed in 1 year of follow-up. After total proctocolectomy, the number of stools may increase and soiling may occur due to changes in the stool properties, which may reduce quality of life. However, the anal function is often maintained after IPAA for ulcerative colitis [10, 11], and it is likely that the outcome will be the same after IPAA for different diseases. In the present case, the number of stools after surgery was about four per day and there was no soiling; the patient was satisfied with the outcome. There are reports that soiling after IPAA is more likely in patients older than 55 years [12, 12]. As our patient was in his 40 s, the preoperative anal sphincter function was maintained, which may have led to the good outcome after IPAA.
