Accurate diagnosis of UC and CD has major implications on the choice of surgical treatment and long-term prognosis. The controversial issue of IC has become fundamental in the so-called pouch era. The need to obtain a differential diagnosis rises from the data widely accepted that ileoanal anastomosis should be contraindicated in patients with Crohn's colitis. Panis et al.  reported a 10% rate of pouch failure in highly selected patients with confirmed preoperative diagnosis of CD. It has to be highlighted that none of these patients had a history of anal lesions or small-bowel involvement. However, most series reported in the literature show poor outcomes after IPAA in CD patients [28-30]. Keighley  found a 52% rate of pouch failure in patients with CD. Mylonakis , analysing patients with CD submitted to IPAA and IRA, reported 47.8% of pouch excision compared with 8% of rectal excision, respectively. Similarly, Brown et al.  reported a 56% rate of pouch failure in CD patients compared with 6% UC and 10% IC patients. Fazio et al.  reported that more than 50% of patients who developed late perianal fistulas after IPAA suffer from CD. On the other hand, Sagar et al.  found a 53% failure rate in patients with preoperative diagnosis of CD versus 41% in those with postoperative diagnosis.
Concerns are raised based on the assumption, not widely accepted, that IC might present with a clinical course comparable with Crohn's colitis or, at least, imply a significant risk of evolution of Crohn's colitis. In fact, many Authors describe significantly higher rates of complications and failure in IC patients compared with UC so that, in their opinion, IPAA
should be contraindicated in cases without a firm preoperative diagnosis. Considering IC as an evolutionary diagnosis with a significant risk of change into CD, Marcello et al.  advise some caution in offering IPAA procedure in patient with IC until a certain diagnosis is obtained. They reported an incidence of perianal complications and pouch failure of 23% and 2%, respectively, in patients with UC; 44% and 12%, respectively, in IC patients and 63% and 37% in patients with CD. In addition, only 3% of UC patients where successively diagnosed as having CD compared with 13% of IC patients. Other reports confirm these data [36-39], with rates of perianal complications significantly higher in IC (30-50% vs 3-20%) and consequent higher risk of failure (19-28% vs 0.4-8%, respectively). Gramlich et al.  found a ten-times more frequent incidence of pelvic sepsis after IPAA in IC versus UC patients. Odze  reported that about 20% of IC patients develop severe septic pouch complications compared with 10% in UC and 40% in CD. On the other hand, many authors [8,28, 30,41-43] do not confirm these trends and suggest that there is no significantly increased risk in constructing a pouch-anal anastomosis in IC patients compared with UC patients. Yu et al. , from the Mayo Clinic group, in a large series of 1,437 patients with UC and 82 with IC, reported higher rates of pouch-related complications in the IC group; however, 15% of IC patients, after long-term follow-up, had their diagnosis changed to CD. When CD patients where considered in a separate group, complication rates and functional outcome were similar in the remaining IC and UC patients.
The presence of these conflicting results in the literature could be related to how IC is defined. In fact, when diagnosis of IC is founded only on the pathological appearance of the colectomy specimen, the incidence of complications is increased in IC compared with UC. Otherwise, if diagnosis is made taking into account all available clinical data, incidence of complications and failure rates are similar in the two groups. Since the surgeon might face this controversial dilemma at different times during the patient's clinical history, it is important to select the safest surgical approach. From the practical point of view, the problem is relatively insignificant in patients with fulminant colitis. In fact, these patients must be treated similarly to UC patients, with total abdominal colectomy and Hartmann's pouch. Histologic examination of the specimen will probably provide more accurate information.
Another favourable scenario occurs when suspicion of IC or CD is raised prior to surgical procedure, after mucosal biopsy or due to the occurrence of perianal lesions. The latter, although up to 5% of UC
patients present with perianal disease, should be considered an alarming sign since it might represent a revealing symptom of CD. In this condition, it seems more appropriate to submit patients to repeated biopsies (endoscopic and of the fistula tract), small-bowel instrumental evaluation and careful inspection of intestinal loops at surgery. If the suspicion is consistent with CD, it is indicated to proceed to total abdominal colectomy only. Moreover, some authors observed a significantly higher risk of postoperative anastomotic leak in patients with perianal lesions (21% vs 11.4%, respectively) .
The most important scenario is represented by long-term follow-up of pouch-anal anastomosis in IC patients. As highlighted above, data reported in the literature are still controversial. Our experience consist of 514 patients submitted to IPAA: 427(83%) had UC, 34 (7%) IC and 51 (10%) familial adenomatous polyposis (FAP). Among patients with IC, ten (29.4%) were successively diagnosed as having CD. Incidence of pelvic sepsis was 8.7% in UC patients and 3.8% in IC patients. Incidence of abdominal sepsis was 3.0% in UC and 7.7% in IC. Five out of ten patients (50%) with subsequent diagnosis of CD had their pouch excised for multiple pouch fistulae compared with UC patients (1.8%) who were submitted to pouch excision for postsurgical chronic sepsis. Two patients refused excision, but their loop ileosto-my has to be considered as definitive (Fig. 1).
Among late complications, the cumulative incidence of pouchitis was 28% and resulted in an increase in patients with IC (52.7%) and CD (50%). Late pouch-anal or pouch-vaginal fistulae occurred in 31 cases (6.0%). Only two of the 19 patients with pouch-anal fistula had CD while four among 12 with pouch-vaginal fistulae had IC (Table 1).
We then classified idiopathic colitis submitted to IPAA as UC, CD and IC. Among the last group, we classified three different subgroups (modified from Wells) . The first group consisted of all cases in which diagnosis was impossible: IC "tout court". Another group consisted of colitises not clearly definable as UC but more easily assimilable to them: IC "probable UC". The last group consisted of indeterminate "probable CD", including colitises not clearly identifiable as CD but presenting features that could resemble it. Therefore, the original 34 IC cases resulted in 23 cases of IC not ulteriorly specified, which we called "true" IC. Five cases resulted IC "probable UC" and six cases IC "probable CD". Finally, a careful retrospective examination of the surgical specimen combined with clinical history of the 23 patients with "true" IC allowed us to extrapolate four more cases of confirmed CD.
Clinical outcome of patients with IC varies. IC and the indeterminate forms "probable UC" have an absolutely similar outcome to UC. Out of the ten patients with sure CD, five were submitted to demolition of the reservoir for disease recurrence. The other five are in good health although one reported recurrent episodes of pouchitis. Finally, patients with IC "probable CD" have an acceptable outcome although the incidence of pouchitis seems to be higher. Dayton et al.  reported that patients with IC "probable CD" present a significantly higher risk of pouch excision compared with those with "true" IC and IC "probable UC". Similarly, Tekkis et al.  found an increased risk of failure in CD or IC favouring CD patients (57.5% vs 11.5% in UC or IC favouring UC).
We can conclude that "true" IC and IC "probable UC" can be treated similarly to patients with certain
Fig. 1. Long-term follow-up
Table 1. Late complications
Pouchitis Pouch excision Pelvic sepsis Abdominal sepsis
UC diagnosis. Moreover, preoperative diagnosis of CD represents in our opinion a contraindication to IPAA although long-term results in our series are satisfactory in almost 50% of these cases. Finally, when preoperative diagnosis of IC "probable CD" is made, total abdominal colectomy is advisable, and if the histologic evaluation of the specimen confirms such diagnosis, it is worthwhile to wait at least 2 years then proceed to IPAA only in those cases where no signs of small-bowel disease occurred during the follow-up.
Analysis of our personal experience leads us to some considerations:
We believe that the development of late pouchanal or pouch-vaginal fistulae does not necessarily indicate CD, unlike some authors who believe it is reasonable to classify patients with pouch fistula as CD [35, 47, 48].
The diagnosis of IC does not necessarily mean evolution to CD and worse outcome.
Was this article helpful?
Moles, warts, and other unsightly irregularities of the skin can be bothersome and even embarrassing. They can be removed naturally... Removing Warts and Moles Naturally! If you have moles, warts, and other skin irregularities that you cannot cover up affecting the way you look, you can have them removed. Doctors can be extremely expensive. Learn the natural ways you can remove these irregularities in the comfort of your own home.