Optimum dosage of ispaghula husk in patients with irritable bowel syndrome: correlation of symptom relief with whole gut transit time and stool weight.

To determine the optimum dose of ispaghula husk in patients with irritable bowel syndrome (IBS) and to assess the correlation, if any between the relief in patients' symptoms and the whole gut transit time, and the increase in stool weight, a two part study was carried out. In part 1, 14 male patients were given ispaghula husk in increasing doses of 10 g, 20 g, and 30 g a day for a duration of 17 days each (14 days of study period + three days of stool collection). Ten patients completed the trial. The symptom score improved significantly with all the three doses of ispaghula. Both 20 g and 30 g doses of ispaghula were superior to the 10 g dose but there was no significant difference between the 20 g and 30 g doses. There was a significant (p less than 0.001) increase in the daily stool weight with 10 g dose of fibre with further significant increases with the 20 g and 30 g doses. A positive correlation was seen between the improvement in the symptom score and the increase in stool weight with the 10 g dose of ispaghula but not with the 20 g and 30 g doses. Whole gut transit time remained fairly constant throughout the study period and there was no relationship with either the dose of ispaghula, the alteration in stool weight, or the improvement in the patients symptoms. Ten patients completed part 2 of the study in which ispaghula husk was given in the same dose (10 g, 20 g, and 30 g) but in a random order and with a "washout" period of one week between individual doses. Again all the three doses of ispaghula produced a significant improvement in the symptoms; 20 g and 30 g doses were equally effective and both were significantly superior to the 10 g dose. Assessed individually, all the three symptoms improved significantly; improvement in constipation and pain abdomen was more pronounced than diarrhoea. It is concluded that the optimum dose of ispaghula husk in irritable bowel syndrome is 20 g per day. There is some correlation between the increase in stool weight and the improvement in symptom score but the whole gut transit time remains unchanged despite alterations in stool weight and patients' symptoms.