464 Archives ofDisease in Childhood 1996; 74: 464-468 CURRENT TOPIC Arch Dis Child: first published as 10.1136/adc.74.5.464 on 1 May 1996. Downloaded from Fibrosing colonopathy in cystic fibrosis Rosalind L Smyth In 1994, the first case reports of colonic stric- The decision about when to operate may tures (now referred to as fibrosing colono- not be straightforward, except in children pathy) in children with cystic fibrosis appeared who have large bowel obstruction. Some in the medical literature.1-5 The initial case children have been operated on because of reports described patients who presented with intractable diarrhoea, faecal incontinence, intestinal obstruction and required surgical anorexia, and weight loss.4 5 In a number of resection of a thickened and narrowed area of children who presented with evidence of colon.' The only aspect of these children's extensive involvement of the colon, defunc- management that had changed was a switch to tioning ileostomies have been performed in new 'high strength' pancreatic enzyme pre- the hope that by diverting faeces from the parations about 12 months previously. It was colon some of the changes may resolve and a suggested that use of these preparation may be more limited resection may subsequently be associated with this condition. Abdominal undertaken. The experience in some of these complaints occur frequently in cystic fibrosis; cases has been that rather than improving, for example the incidence of Crohn's disease the narrowing has progressed and become has been reported to be 17 times higher more extensive,7 rendering subsequent than the general population.6 It was not clear surgery more difficult. I am aware of a num- initially whether these cases represented varia- ber of children who have presented with dif- tions of the normal pathology reported in fuse involvement of the colon, and in whom cystic fibrosis, or a new entity. In some resection or ileostomy has been avoided. instances, the clinical and radiological features These children have remained well on con- were suggestive of Crohn's disease, or an servative management. It would therefore inflammatory colitis, but the histological find- seem wise to manage these children conserva- ings were strikingly different. It is the patho- tively where possible, but with very careful http://adc.bmj.com/ logical findings (described below), not clinical monitoring and annual ultrasound to reported previously in cystic fibrosis, which assess bowel wall thickness. have characterised this condition. I will attempt to review the clinical, radiological, and histological features of this condition and Radiological features discuss the current evidence on aetiology. A thickened colon wall may be evident on plain abdominal and may be confirmed radiograph on September 26, 2021 by guest. Protected copyright. by ultrasonography. The features of fibrosing Clinical features colonopathy on ultrasound include bowel wall The clinical presentation of fibrosing thickening of more than 2 mm,9 reduced peri- colonopathy is non-specific. Abdominal pain, stalsis, and free fluid associated with the distension, vomiting, and constipation are fre- affected areas.10 We investigate all children quent features7 and have led initially to con- who present with abdominal pain with an fusion with distal intestinal obstruction abdominal radiograph and bowel ultrasound. syndrome.8 However, these symptoms fail to Distal intestinal obstruction syndrome is the respond to the usual medical management of most frequent finding." If both are normal, distal intestinal obstruction syndrome and the then fibrosing colonopathy is very unlikely.'2 If patient may progress to subacute and later there are any of the above abnormalities on acute obstruction. Children have also pre- ultrasound, then contrast studies are indicated. sented with symptoms of a colitis, with diar- The findings on contrast enema fall into to rhoea, sometimes containing blood and main groups.'3 In the first, the intramural mucus, abdominal pain, and anorexia.5 Ascites widening causes a localised narrowing of the has been reported and chylous ascites has colon without mucosal abnormality. There been evident in some patients at operation4 may be evidence of obstruction. The main dif- (R Nelson, personal communication). The ferential diagnosis is Crohn's disease. The reasons for this last observation are not entirely second group of patients have evidence of Respiratory Unit, clear, although it has been suggested that there more extensive colonic inflammation, loss of Royal Liverpool may have been obstruction of mesenteric lym- haustration, and marked mucosal abnormality. Children's Hospital, Alder Hey, Liverpool phatic vessels. The onset of symptoms may be The differential diagnosis is wide and includes L12 2AP insidious, over many months, so prompt inves- fibrosing colonopathy, Crohn's disease, ulcera- of children with of tive Correspondence to: tigation presenting any colitis, pseudomembraneous of infective Dr Smyth. these symptom complexes is clearly advisable. colitis. Fibrosing colonopathy in cystic fibrosis 465 Pathological diagnosis cohort evaluation was initiated to address the Fibrosing colonopathy is a histopathological first two of these aims. Details were requested diagnosis and requires either a resection speci- of all cystic fibrosis patients who had under- men or a full thickness biopsy. Not all patients gone surgery in between 1984 and 1994. Arch Dis Child: first published as 10.1136/adc.74.5.464 on 1 May 1996. Downloaded from believed to have this condition have required Where small or large bowel had been resected surgery and suitable biopsy material can be or biopsied, the histological sections were obtained only by laparotomy. Colonoscopic reviewed. It was well recognised that a number biopsies, which usually sample the mucosa of cases had presented with clinical and radio- alone, are generally unsatisfactory. One is logical features of fibrosing colonopathy, but therefore left with the difficult situation of had not required surgery and histological trying to identify the condition by clinical and material was not therefore available. Because radiological criteria. Because of the range of the diagnosis in these cases was less precise, it possible differential diagnoses, even after all was decided not to include them in the case- imaging has been completed I believe that control study. Fourteen cases of fibrosing definitive diagnosis is not possible in such colonopathy were identified, the first occurring cases. in April 1993. Twelve were boys and six had The histopathological features are patho- received some or all of their care in Liverpool. gnomonic.14 The stenoses, which are fre- A nested case-control study was then under- quently long segment, result from submucosal taken, where each case was matched by date of thickening by fibrous connective tissue. This birth with four controls taken from the UK leads to intraluminal narrowing which occurs cystic fibrosis survey. The case-control studied without a significant reduction in the external identified an association between fibrosing diameter ofthe colon. The epithelium is gener- colonopathy and use of high strength pan- ally intact with very little inflammatory change creatic enzyme preparations, but not the use of in the affected areas.' In the original report of low strength preparations. The association this condition the patients were described as with high strength preparations was dose having a localised stricture in the ascending related, temporally credible, and biologically colon, although after surgical resection, one plausible. Not all high strength products were, patient subsequently developed a second stric- however, found to be associated. Two similar ture,1 suggesting that the disorder may have products, Pancrease HL (Cilag) and Nutrizym been more widespread that originally sus- 22 (Merck) were found to be associated with pected. Other reports have described patients fibrosing colonopathy, but Creon 25000 with extensive fibrosis throughout the colon at (Duphar) was not. presentation. To emphasise the long segment The study also demonstrated that cases were colonic involvement and the distinction more likely than controls to have taken laxa- between this condition and inflammatory stric- tives in the 12 months before surgery. A tures that are typically focal, the term fibrosing possible explanation for this was that when colonopathy is now used in preference to patients with fibrosing colonopathy initially http://adc.bmj.com/ 'colonic strictures'. presented they had abdominal pain. Some were thought to have distal intestinal obstruc- tion syndrome and were therefore treated with Aetiology offibrosing colonopathy laxatives. This illustrates the difficulty of infer- The first reports of fibrosing colonopathy and ring causality on the basis of an association the suggested link with high strength pan- demonstrated in an observational case-control creatic enzyme came like a bomb- products study. on September 26, 2021 by guest. Protected copyright. shell. Regulatory authorities moved swiftly on There were two main hypotheses generated both sides of the Atlantic. In the UK, the from this case-control study. The first was that Committee on Safety of Medicines recom- the disorder is due to one of the active con- mended that patients being treated with high stituents of pancreatic enzyme preparations. strength pancreatic enzyme preparations The use of high strength enzyme preparations should be reviewed and unless there