MINI-REVIEW Colonic disorders in adult cystic fibrosis Hugh Chaun BM FRCP FRCPC H Chaun. Colonic disorders in adult cystic fibrosis. Can J Troubles du côlon chez les adultes atteints de Gastroenterol 2001;15(9):586-590. By 1996, the median sur- vival of patients with cystic fibrosis (CF) in North America had mucoviscidose increased to 31 years. With the markedly improved life RÉSUMÉ : En 1996, la survie moyenne des patients atteints de muco- expectancy, many CF patients are now adults. There is an asso- viscidose (ou FK pour fibrose kystique) en Amérique du Nord était ciated increased risk of certain colonic disorders, and the emer- passée à 31 ans. Compte tenu de cette nette amélioration de l’espérance gence of other previously unrecognized disorders, in adult CF de vie, de nombreux patients atteints de FK atteignent désormais l’âge patients. The distal intestinal obstruction syndrome (DIOS), adulte. Or, on note un risque accru à l’égard de certains troubles du côlon which is more common in older patients, is a frequent cause of et l’émergence d’autres maladies qui n’avaient pas encore été notées chez abdominal pain. Intussusception may complicate DIOS; other les patients adultes atteints de FK. Le syndrome d’obstruction intestinale distale (SOID), qui est plus fréquent chez les patients plus âgés, est une differential diagnoses include appendiceal disease, volvolus, cause fréquente de douleur abdominale. L’intussusception peut compli- Crohn’s disease, fibrosing colonopathy and colonic carcinoma. quer le SOID. D’autres diagnostics différentiels sont : l’appendicite, le The diagnosis of acute appendicitis, although uncommon in volvulus, la maladie de Crohn, la colopathie fibrosante et le cancer du patients with CF, is often delayed, and appendiceal abscess is a côlon. Le diagnostic de l’appendicite aiguë, bien que rare chez les frequent complication. The prevalence of Crohn’s disease in CF patients atteints de SK, est souvent retardé et l’abcès de l’appendice est has been shown to be 17 times that of the general population. une complication fréquente. La maladie de Crohn serait 17 fois plus pré- Right-sided microscopic colitis is a recently recognized entity in valente chez les patients atteints de SK que dans la population en CF of uncertain clinical significance. Fibrosing colonopathy has général. La colite microscopique du côté droit est une entité qui a récem- been confined mostly to children with CF, attributed to the use ment été reconnue dans la FK. On ignore quelle est sa portée clinique. of high strength pancreatic enzyme supplements, but it has been La colopathie fibrosante a surtout été observée chez les enfants atteints reported in three adults. Nine cases of carcinoma of the large de mucoviscidose. Elle est attribuée à l’utilisation de suppléments enzy- intestine have been reported worldwide, associated with an matiques pancréatiques à forte dose, mais on l’a également signalée chez trois adultes. Neuf cas de cancer du côlon ont été rapportés dans le apparent excess risk of digestive tract cancers in CF. Despite high monde, associés à un risque apparemment plus grand de cancer de l’ap- carrier rates of Clostridium difficile in patients with CF, pareil digestif dans la FK. Même si les patients atteints de FK sont sou- pseudomembranous colitis is distinctly rare, but severe cases vent porteurs de Clostridium difficile, la colite pseudomembraneuse est complicated by toxic megacolon have been reported. In these rare, mais des cas graves, compliqués de mégacôlon toxique ont été patients, watery diarrhea is often absent. Adult CF patients with dénombrés. Chez ces patients, la diarrhée liquide est souvent absente. refractory or unexplained intestinal symptoms merit thorough Les patients adultes atteints de FK, qui présentent des symptômes investigations. intestinaux rebelles ou inexpliqués doivent être soumis à des analyses plus approfondies. Key Words: Adults; Colonic disorders; Cystic fibrosis This paper was first presented at the Bockus International Society of Gastroenterology Scientific Congress, August 31 to September 3, 1998, Graz, Austria Adult Cystic Fibrosis Clinic and Division of Gastroenterology, Department of Medicine, St Paul’s Hospital, and University of British Columbia, Vancouver, British Columbia Correspondence and reprints: Dr H Chaun, Suite 1402 – 805 West Broadway, Vancouver, British Columbia V5Z 1K1. Telephone 604-872-0717, fax 604-872-7921, e-mail [email protected] Received for publication November 29, 1999. Accepted November 29, 1999 586 Can J Gastroenterol Vol 15 No 9 September 2001 Colonic disorders in adult cystic fibrosis ystic fibrosis (CF) is the most common life-threatening of peritoneal signs. Ultrasound may help in the recognition Cinherited disease of white populations (1). One in of intussusception, appendiceal disease and fibrosing every 20 or 30 white Canadians probably carries the CF colonopathy. Water-soluble contrast enema (eg, Gastro- gene, and approximately one in every 2000 or 3000 is born grafin; Bracco Diagnostics Canada Inc, Canada) is most with CF in this population (2). CF is much rarer in non- helpful in diagnosis, and may aid in the treatment of DIOS white populations, and occurs in one in 17,000 black and intussusception. A balanced iso-osmotic polyethylene Americans (3), one in 80,000 Native Americans (4) and glycol lavage solution (eg, Go-lytely; Pharmascience, one in 100,000 Asians (5). Advances in the management of Canada) is effective in treating DIOS (19). Adult patients CF have markedly improved survival. Once confined to may require several litres to clear the obstructive mass, and children, CF is now also a disease of adults. Before 1950, the may need it repeated for two or three days. median survival was one year (6). In Canada, the median Constipation is common in adults with CF – up to three survival age increased from 15 years in the 1970s to 28 years times more frequent than DIOS (20). Sometimes it may in the decade 1980 to 1989. By 1996, the median survival complicate excessive doses of pancreatic enzymes or it may had increased to 31 years, and 36% of patients registered result from the sheer bulk of stool secondary to longstand- with the United States Cystic Fibrosis Foundation were ing malabsorption (17). Intestinal dysmotility may be an adults (6). It has been estimated that patients with CF born aggravating factor. Careful adjustment of the pancreatic today can have a life expectancy of beyond 40 years (7,8). enzyme dosage, high fibre and increased fluid intake, and Enhanced longevity is associated with increased preva- the use of mineral oil or lactulose are often helpful. DIOS lence of various colonic disorders and the emergence of needs to be considered in resistant patients. others that were previously unrecognized. The increased incidence of Crohn’s disease (9), the increased risk of can- INTUSSUSCEPTION cer (10) and the occurrence of fibrosing colonopathy, now Intussusception is a rare complication of CF but occurs reported also in adults (11,12), are examples. most commonly in older patients (20). It was reported in 5% of patients in one adult series and in 20% of those pre- DISTAL INTESTINAL OBSTRUCTION senting with intestinal obstruction (16). A tenacious fecal SYNDROME bolus adherent to the mucosa may act as the lead point. CF is caused by abnormality of a gene on the long arm of The intussusception is frequently ileocolic in location (21). chromosome 7 known as the cystic fibrosis transmembrane It may occur as a complication of DIOS and is often recur- conductance regulator (CFTR) gene. It encodes a cAMP- rent. Its diagnostic evaluation and management have been regulated chloride channel and is located on the apical described under DIOS. Failure to reduce the intussuscep- membrane of many epithelial cells, including pancreatic tion or suspicion of appendiceal disease are indications for tubules and intestinal crypt enterocytes (13). Ion transport laparotomy. abnormalities have been demonstrated in intestinal tissues Intestinal volvulus complicating CF has been reported of CF (14). in patients with intestinal obstruction and a history of Defects in crypt chloride and fluid secretion cause the abdominal surgery (17). production of viscous intestinal contents in CF. Distal intestinal obstruction syndrome (DIOS), previously termed APPENDICITIS AND APPENDICEAL ABSCESS meconium ileus equivalent, results from the effects of pan- Despite the postmortem findings that the appendiceal lumen creatic insufficiency and the intestinal secretion abnormal- is often swollen and obstructed by inspissated eosinophilic ity. Abnormal intestinal motility may also be a contributing secretions, acute appendicitis is an uncommon complica- factor (15). It is associated with impaction of inspissated tion of CF, occurring in 1% to 2% of patients (22,23). mucofeculent contents in the terminal ileum, cecum and However, the difficulty and delay in diagnosis may lead to proximal colon. The reported incidence of DIOS varies serious complications such as perforation and chronic widely. In an earlier review of adult patients with CF, DIOS appendiceal abscess (24). Acute appendicitis in CF occurs occurred in 24% of patients (16). However, possibly follow- over a wide age range, including adults (22). In older ing the introduction of microspheric pancreatic enzymes patients, the large, distended appendix may act as a lead (17), DIOS was reported in only 4% of adolescent and adult point for intussusception (22). The diagnosis of appen- patients with CF (18). The disorder may be precipitated by diceal disease in CF may be masked by antibiotic therapy. poor compliance to pancreatic enzyme therapy and postop- The clinical presentation may mimic DIOS, intussuscep- erative use of opiate drugs. Recurrent colicky abdominal tion and Crohn’s disease (17). Laparotomy must be consid- pain and a palpable mass in the right lower quadrant, with ered in the presence of tenderness, guarding, and leukocy- or without other evidence of intestinal obstruction, are tosis or fever, if diagnostic imaging studies are unhelpful. characteristic features of DIOS. A plain abdominal radi- ograph shows the impacted fecal mass.