Determination of large bowel length and loop complexity in patients with acromegaly undergoing screening colonoscopy

Summary Background  Patients with acromegaly are at moderately increased risk of developing colorectal cancer and may be considered for screening colonoscopy. In turn, large bowel dimensions may be increased in these patients, factors that predict for increased risk of serious complications such as perforation. Objective  To evaluate this risk potential, we measured large bowel length and loop complexity using magnetic endoscopic imaging (MEI). Design  Case–control study in 25 unselected patients with acromegaly (mean age 56 years) vs. 41 nonacromegalic controls (mean age 60 years) undergoing screening colonoscopy. Measurements  MEI parameters were determined and age- and sex-adjusted mean differences calculated. The dependency of total large bowel length on various demographic and disease-related factors (e.g. GH exposure, IGF-I and IGFBP-3 concentrations) was assessed using regression techniques. Results  Total large bowel length was increased by 20%[95% confidence interval (CI) 9–31%] in patients with acromegaly compared with controls (unadjusted and adjusted; P-values < 0·001). Acromegaly was also associated with increased time taken to reach the caecum (P = 0·01) and increased pelvic loop complexities (5/25 vs. 1/41, Fisher's exact test: P = 0·03). Total large bowel length was predicted by age at colonoscopy (P = 0·003) and patient height (P = 0·03), but not by surrogate biochemical markers of disease activity. Conclusions  Acromegaly is associated with increased large bowel length and loop complexity making colonoscopy technically challenging, and theoretically increasing the risk of serious complications. Patients need to be counselled accordingly, and appropriate resources with experienced staff allocated.