A descriptive study of colorectal function in adults with Prader-Willi Syndrome: high prevalence of constipation.

BACKGROUND: Some patients with Prader-Willi Syndrome (PWS) have symptoms of constipation, but bowel function in PWS has never been systematically evaluated. The aim of the present study was to describe colorectal function in PWS by means of validated techniques. METHODS: Twenty-one patients with PWS (14 women, age 17-47 (median = 32)) were evaluated with the Rome III constipation criteria, stool diary, digital rectal examination, rectal diameter assessed from transabdominal ultrasound, and total gastrointestinal transit time (GITT) determined with radio-opaque markers. Results were compared with those of healthy controls. RESULTS: Among PWS patients able to provide information for Rome III criteria, 8/20 (40%) fulfilled the criteria for constipation. Most commonly reported symptoms were a feeling of obstructed defecation (8/19, 42%), <3 defecations per week (8/17, 47%), straining during defecation (7/19, 37%) and lumpy or hard stools (6/19, 32%). Rectal diameter did not differ between PWS (median 3.56 centimeters, range 2.24-5.36) and healthy controls (median 3.42 centimeters, range 2.67-4.72) (p = 0.96), but more PWS patients (13/20; 65%) than healthy controls (3/25; 12%) (p < 0.001) had fecal mass in the rectum. Median GITT was 2.0 days (range 0.5-4.4) in PWS versus 1.6 (range 0.7-2.5) in the control group (p = 0.26). However, GITT was >3 days in 5/21 (24%) of PWS and none of the controls (p = 0.047). CONCLUSION: Constipation is very common in PWS. Patients with PWS have an increased prevalence of prolonged GITT and palpable stools in the rectum at digital rectal examination.

Magnet tracking allows assessment of regional gastrointestinal transit times in children.

BACKGROUND: Data on small intestinal transit time in healthy children are lacking, and normal values for gastric emptying and colonic transit time are sparse. Conventional methods, including radiopaque markers, scintigraphy, and PillCam™ involve radiation or require the child to swallow a large pill. The minimally invasive, radiation-free Motility Tracking System-1 (MTS-1) has been introduced for description of gastrointestinal motility in adults. The aim of the study was to evaluate the MTS-1 for assessment of gastrointestinal transit times and motility patterns in healthy children. METHODS: Twenty-one healthy children (nine girls), median age 10 (range 7-12) years were included. For evaluation with MTS-1, a small magnetic pill was ingested and tracked through the gastrointestinal tract by a matrix of 16 magnetic sensors placed behind a nonmagnetic bed. The children were investigated for 8 hours after swallowing the magnetic pill and again for 4 hours the following morning. After leaving the unit, each child came back after every bowel movement to determine if the pill had been expelled. RESULTS: Nineteen children could swallow the pill. Characteristic contraction patterns were identified for the stomach (three per minute), small intestine (9-11 per minute), and colon (4-5 per minute). Median total gastrointestinal transit time was 37.7 (range 9.5-95.8) hours, median gastric emptying time was 37 (range 2-142) minutes, median small intestinal transit time was 302 (range 164 to >454) minutes, and median colorectal transit time was 38.1 (range 5.6-90.0) hours. CONCLUSION: MTS-1 allows minimally invasive evaluation of gastrointestinal motility in children. Use of the method is, however, restricted by the nonambulatory setup.

Gastrointestinal transit times and motility in patients with cystic fibrosis.

OBJECTIVE: Patients with cystic fibrosis (CF) often suffer from gastrointestinal (GI) dysfunction including obstructive symptoms, malabsorption and pain, but the underlying pathophysiology remains obscure. AIM: To compare GI motility and transit times in CF patients and healthy controls. MATERIAL AND METHODS: Ten CF patients (five women, median age 23) with pancreatic insufficiency were studied. Total gastrointestinal transit time (GITT) and segmental colonic transit times (SCTT) were assessed by radiopaque markers. Gastric emptying and small intestinal transit were evaluated using the magnet-based motility tracking system (MTS-1). With each method patients were compared with 16 healthy controls. RESULTS: Basic contraction frequencies of the stomach and small intestine were normal, but the pill reached the cecum after 7 h in only 20% of CF patients while in 88% of controls (p = 0.001). Paradoxically, velocity of the magnetic pill through the upper small intestine tended to be faster in CF patients (median 1.1 cm/min, range 0.7-1.7) compared with controls (median 1.0 cm/min, range 0.6-1.7) (p = 0.09). No statistically significant differences were found in median gastric emptying time (CF: 58 min, range 6-107 vs. healthy: 41 min, range 4-125 (p = 0.24)), GITT (CF: 2 days, range 0.5-3.3 vs. healthy: 1.5 days, range 0.7-2.5 (p = 0.10)), right SCTT (CF: 0.5 day, range 0-1.1 vs. healthy: 0.4 day, range 0-1.0 (p = 0.85)), or left SCTT (CF: 1.0 day, range 0-2.2 vs. healthy 0.6 day, range 0.2-1.2 (p = 0.10)). CONCLUSIONS: In spite of normal contraction patterns, overall passage through the small intestine is significantly delayed in CF patients while upper small intestinal transit may be abnormally fast.

24-hour rectal manometry for overactive bladder.

PURPOSE: We describe prolonged rectal manometry used to characterize rectal motor activity patterns and possible rectum-bladder interaction during defecation and micturition in children with nonneuropathic overactive bladder. MATERIALS AND METHODS: We evaluated 10 children with a mean +/- SD age of 9.7 +/- 1.3 years with overactive bladder who underwent urodynamics and 24-hour rectal manometric recording. All records were analyzed visually. Rectal contractions were defined as pressure runs exceeding 5 cm H(2)O and lasting longer than 5 seconds. RESULTS: Three rectal motility patterns were noted in all children, including 1) slow tonic pressure waves with a frequency of 3 to 12 per hour, b) rectal motor complexes with a frequency of 3 to 10 per minute and c) single contractions 10 to 30 seconds in duration. The median nocturnal duration of rectal motor complexes was longer than that during the day (16.3 minutes, range 10.8 to 18.8 vs 11.0, range 8.9 to 12.6, p <0.05). As a percent of time, median total contraction time was greater at night than during the day (51.9%, range 42.6% to 56.9% vs 30.6%, range 19.4% to 49.3%, p <0.05). Characteristic rectal activity was seen during defecation and voiding but no bladder-rectum interaction was detected. CONCLUSIONS: We identified 3 rectal motility patterns in all children with overactive bladder. Like the upper gastrointestinal tract, the rectum shows some periodic motor activity, which is more frequent at night. No association was observed between bladder and rectal activity during micturition and defecation.

Transabdominal ultrasound of rectum as a diagnostic tool in childhood constipation.

PURPOSE: We tested whether transverse rectal diameter measured by ultrasound could identify rectal impaction, investigated whether transverse diameter is enlarged in constipated children compared to healthy children and evaluated transverse diameter during treatment of constipation. MATERIALS AND METHODS: A total of 51 children 4 to 12 years old were included in the study. Of the children 27 (mean age 7.0 +/- 1.8 years) had been diagnosed with chronic constipation by Rome III criteria and 24 (9.1 +/- 2.7 years) were healthy controls. All patients underwent a thorough medical history and physical examination, including digital rectal examination and measurement of rectal diameter by transabdominal ultrasound. Constipated children underwent repeat investigations after 4 weeks of laxative treatment. RESULTS: Average rectal diameter of children with negative digital rectal examination was 21 +/- 4.2 mm (mean +/- SD), leading to the approximation that a value greater than 29.4 mm (mean +/- 2 SD) indicates rectal impaction. All children with rectal impaction identified by digital examination had a rectal diameter larger than 29.4 mm. Moreover, constipated children had a significantly larger rectal diameter (42.1 +/- 15.4 mm) than healthy children (21.4 +/- 6.0 mm, p <0.001). After 4 weeks of laxative treatment constipated children had a significant reduction in rectal diameter (mean 26.9 +/- 5.6 mm, p <0.001). CONCLUSIONS: Transverse rectal diameter seems to be a valuable tool to identify rectal impaction and may replace digital rectal examination. Constipated children have a significantly larger rectal diameter compared to healthy children, and when constipation is treated the diameter is reduced significantly.