Irritable bowel syndrome: is the search for lactose intolerance justified?

OBJECTIVES: To determine if confirmation of hypolactasia offers any benefit to the dietary treatment of patients with irritable bowel syndrome (IBS). METHODS: One hundred and twenty-two consecutive IBS patients (37 male, 85 female) were given lactose hydrogen breath tests (LHBT). Those with positive LHBT followed a low lactose diet for 3 weeks. Those improving on the diet were given double-blind, placebo-controlled challenges (DBPCC) with 5 g, 10 g and 15 g of lactose and a placebo, to confirm lactose intolerance. Those who did not respond to the low lactose diet followed either an exclusion or low fibre diet. Symptoms scores were kept prior to the LHBT, 8 h post-LHBT and daily whilst following any dietary change. Patients with negative LHBT returned to clinic and subsequent dietary interventions were recorded. RESULTS: LHBT was positive in 33/122 (27%) IBS patients. Syrr otom scores prior to LHBT were not significantly different between the two groups, but after LHBT the symptoms in the positive group were significantly worse. Twenty-three patients followed a low-lactose diet of which only nine (39%) improved. Six who did not improve followed an exclusion diet, three improved and all were intolerant of milk. Three tried a low fibre diet with two improving. DBPCC were inconclusive. In the negative LHBT group 35 agreed to try a diet and 24 improved (69%). Eight were intolerant of cow's milk. CONCLUSIONS: Use of a low lactose diet was disappointing in IBS patients with lactose malabsorption. Food intolerance was demonstrated in IBS patients with positive or negative LHBT and milk was identified as a problem in both groups. DBPCC were inconclusive. There appears to be little advantage in trying to separate patients who malabsorb lactose from others with IBS.

Controlled trial of oligofructose in the management of irritable bowel syndrome.

A double-blind crossover trial of oligofructose (Raftilose P95) 2 g three times daily against sucrose (1 g) three times daily was performed in patients suffering from irritable bowel syndrome. Each treatment was followed for 4 wk. Patients consumed a standardized diet during the last 14 d of each treatment period, and symptoms were assessed using a previously validated questionnaire. Fecal weight and pH, whole-gut transit time and fasting breath hydrogen concentrations were measured at the start of the study and at the end of each treatment period. Oligofructose produced no significant change in any of these parameters even when patients were divided into those with predominant diarrhea (n = 14) and those with predominant constipation (n = 7). Oligofructose at a dose of 6 g/d had no therapeutic value in patients with irritable bowel syndrome.

An open-label phase I/II dose escalation study of the treatment of pancreatic cancer using lithium gammalinolenate.

There are currently no satisfactory treatments for inoperable pancreatic cancer. Median survivals for untreated patients are of the order of 100 days and, with one exception, no chemotherapy or radiotherapy regime has been found to produce a worthwhile extension of life with reasonably tolerable side effects. Gamma-linolenic acid (GLA) has been found to kill about 40 different human cancer cell lines in vitro without harming normal cells. The lithium salt of GLA (LiGLA) can be administered intravenously and a dose escalation study of a 10 day infusion followed by oral therapy in patients with inoperable pancreatic cancer was carried out in 48 patients in two centres. Peripheral venous infusion caused thrombophlebitis but this could be avoided by infusing via a central vein with appropriate heparinisation. Too rapid infusion caused haemolysis which could be avoided by slow dose escalation in the first few days and maintenance of plasma lithium below 0.8 mmol/l. Doses ranged from 7 to 77g/patient cumulatively delivered over 2-12 days. Other than the above described events there were no important side effects and patients felt well during the infusions. A Kaplan-Meier analysis showed that survival was not significantly influenced by which centre the patients were treated in, the sex of the patients or the presence or absence of histological confirmation. The presence or absence of liver metastases, the patients' Karnofsky scores and the-dose of LiGLA had significant effects on survival from treatment. A Cox proportional hazards model revealed similar results: in both centres, in both sexes, and in patients with and without liver metastases according to the model the highest doses of LiGLA were associated with longer survival times as compared with the lowest doses. LiGLA deserves investigation in a randomised prospective study.