You hit the nail on the head, Nawlinscate!
Endoscopy 2002 Jun;34(6):435-40
Patient pain during colonoscopy: an analysis using real-time magnetic endoscope imaging.
Shah SG, Brooker JC, Thapar C, Williams CB, Saunders BP.
Wolfson Unit for Endoscopy, St. Mark's Hospital, Harrow, London, United Kingdom.
BACKGROUND AND STUDY AIMS: Colonoscopy is generally perceived as being a painful procedure. Contributory factors are: stretching of the colonic wall and mesenteric attachments from looping of the instrument shaft, overinsufflation, the degree of torque or force applied to the colonoscope shaft, and patient pain threshold. The aim of this study was to determine the frequency of pain episodes experienced during diagnostic colonoscopy and the corresponding colonoscope configuration, utilizing real-time magnetic endoscope imaging (MEI).
PATIENTS AND METHODS: Consecutive outpatients undergoing colonoscopy were studied. Patients with previous colonic resections were excluded. Procedures were commenced with antispasmodics only, and patient sedation was self-administered whenever significant discomfort was experienced, using a patient-controlled analgesia (PCA) syringe pump. All "demands" were correlated with the MEI record, which was subsequently analysed.
RESULTS: A total of 650 demands were recorded in 102 patients. Seventy-seven percent of all demands occurred with the colonoscope tip in the sigmoid colon, 7 % in the descending colon, 6 % at the splenic flexure, 5 % in the transverse colon, and 4 % in the proximal colon. Ninety percent of all pain episodes coincided with either looping (79 %) or straightening of the colonoscope shaft (11 %); presumed overinsufflation being an infrequent cause of pain (9 %). Of the loops encountered during colonoscopy, the N-sigmoid spiral loop was associated with the majority of pain episodes (56 %). Looping was both more frequent ( P = 0.0002) and less well tolerated in women than in men ( P = 0.0140).
CONCLUSIONS: This study is the first to document pain at colonoscopy accurately. Looping, particularly in the variable anatomy of the sigmoid colon, is the major cause of pain, especially in women. Use of MEI may improve pain control by facilitating the straightening of loops within the sigmoid colon, and by enabling the endoscopist to target patient analgesia.
PMID: 12048623 [PubMed - indexed for MEDLINE]
Gastrointest Endosc 1996 Feb;43(2 Pt 1):124-6
Why is colonoscopy more difficult in women?
Saunders BP, Fukumoto M, Halligan S, Jobling C, Moussa ME, Bartram CI, Williams CB.
Department of Endoscopy, St. Mark's Hospital, London, England.
BACKGROUND: In our experience colonoscopy in women is more difficult than in men. A retrospective review of 2194 colonoscopies performed by a single experienced endoscopist (CBW) showed that 31% of examinations in women were considered technically difficult compared with 16% in men.
METHODS: To investigate a possible anatomic basis for this finding, normal barium enema series from 183 female and 162 male patients were identified. From these barium enemas, measurements of colonic length and mobility were independently taken by two physicians who were unaware of each patient's gender.
RESULTS: Total colonic length was greater in women (median, 155 cm) compared to men (median, 145 cm), p = 0.005, despite women's smaller stature (p < 0.0001). Although there were no significant differences in rectum plus sigmoid, descending, or ascending plus cecum segmental lengths, women had longer transverse colons (female median length, 48 cm; male median length, 40 cm), p < 0.0001. There were no differences in mobility of the descending colon and transverse colon between the sexes, but the transverse colon reached the true pelvis more often in women (62%) than in men (26%), p < 0.001.
CONCLUSIONS: Colonoscopy appears to be a technically more difficult procedure in women. The reason for this may be due in part to an inherently longer colon.
PMID: 8635705 [PubMed - indexed for MEDLINE]