Clinical response to dietary fiber treatment of chronic constipation.

OBJECTIVES: To determine the clinical outcome of dietary fiber therapy in patients with chronic constipation. METHODS: One hundred, forty-nine patients with chronic constipation (age 53 yr, range 18-81 yr, 84% women) at two gastroenterology departments in Munich, Germany, were treated with Plantago ovata seeds, 15-30 g/day, for a period of at least 6 wk. Repeated symptom evaluation, oroanal transit time measurement (radiopaque markers), and functional rectoanal evaluation (proctoscopy, manometry, defecography) were performed. Patients were classified on the basis of the result of dietary fiber treatment: no effect, n = 84; improved, n = 33; and symptom free, n = 32. RESULTS: Eighty percent of patients with slow transit and 63% of patients with a disorder of defecation did not respond to dietary fiber treatment, whereas 85% of patients without a pathological finding improved or became symptom free. CONCLUSION: Slow GI transit and/or a disorder of defecation may explain a poor outcome of dietary fiber therapy in patients with chronic constipation. A dietary fiber trial should be conducted before technical investigations, which are indicated only if the dietary fiber trial fails.

The influence of arginine-vasopressin on stool output and gastrointestinal transit time in healthy volunteers.

OBJECTIVE: It was asked whether continuous infusion of arginine-vasopressin (AVP) could decrease stool output and gastrointestinal transit time in healthy volunteers. DESIGN: Randomised single blind cross-over-design. SUBJECTS: 5 healthy male volunteers. INTERVENTIONS: Continuous s.c. infusion of AVP (7.5 micrograms/d) for one week vs. 0.9% NaCl-solution (placebo). Some days before the experiment started, the volunteers underwent a two-day-thirsting-period (< 500 ml/day). MEASUREMENTS: AVP-levels in serum, urine output, AVP-urine-excretion, stool frequency, stool weight, colonic transit time. RESULTS: As compared to saline infusion both serum-levels of AVP and AVP-excretion in urine were about four times higher during AVP-infusion whereas they were doubled during thirsting. Accordingly urine output was lower when AVP-levels were high. Parameters of colonic motility did not differ significantly (stool frequency 6.8 +/- 0.8/week for placebo vs. 6.8 +/- 0.5/week during AVP, stool weight 200.3 +/- 25.0 g/d vs. 210.6 +/- 21.1 gld, total colonic transit 22.9 +/- 7.0 hours vs. 25.7 +/- 5.8 hours). CONCLUSION: 1. AVP is well absorbed when applied subcutaneously. 2. AVP in the dosage given has no major influence on stool output and gastrointestinal transit time in healthy volunteers.

Polyethylene glycol 4000 for slow transit constipation.

Slow transit constipation is notoriously difficult to treat. We tested whether polyethylene glycole 4000 (PEG) improves slow transit constipation. Eight female outpatients with symptoms of constipation and a colonic marker transit of more than 60 h were included (age 46 +/- 4y, duration of complaints 17 +/- 3y) in a randomised controlled cross-over study. During a 6-week placebo and 6-week PEG-phase (60g PEG/d) the following parameters were measured: 1. subjective well-being with respect to defeacation on a visual analogue scale (-8 cm very bad, +8 cm very good), 2. in the first 5 weeks of each phase, average dose of sodium picosulfate (prescribed as only allowed laxans, dose adjusted and protocolled on a diary by patient) 3. stool frequency, 4. colonic transit of radiopague polythene pellets in the last week of each phase (the use of laxative was strictly prohibited in this last week). Both subjective and objective parameters of colonic function improved significantly. Visual analog scale ratings improved from -4.65, [-8; 0.5] to 4.65, [-8; 7.5]cm (median, range) (p = 0.028), the self-administered dose of sodium picosulfate decreased from 4, [0; 37] to 0, [0; 11] drops per day (p = 0.028), stool frequency increased from 3.1, [1; 30] to 11, [2; 33] defeacations per week (p = 0.017), and total colonic transit decreased from 91, [67; 116] to 43 h, [17; 76]h (p = 0.017). In conclusion, PEG improves colonic function in patients with slow transit constipation subjectively and objectively. PEG should be considered as an additional option in patients refractory to established forms of treatment.