1084 SELECTED SUMMARIES
GASTROENTEROLOGY Vol. 102,No. 3
No significant differences were seen among the three therapies in terms of blood transfusions, length of hospital stay, rate of emergency surgery, or mortality.
Comment. Controlled clinical trials of YAG laser, heater probe, and BPEC have yielded mixed results. However, careful analysis of these trials does suggest that patients at high risk for persistent or recurrent bleeding (clinically significant hemorrhage and endoscopic evidence of active bleeding or an ulcer with a nonbleeding visible vessel) benefit from therapy with BPEC, heater probe, and probably YAG laser. The National Institute of Health Consensus Conference on Therapeutic Endoscopy and Bleeding Ulcers concluded that BPEC and heater (JAMA 1989;262:1369-1372) probe were the two most promising modalities for endoscopic hemostatic therapy and ranked YAG laser at a secondary level. In addition, studies in a canine model have indicated that BPEC and heater probe are the most effective and safest thermal methods for coagulation of bleeding arteries (Gastroenterology 1987;92:11011108).
The article by Hui et al. is an important one for physicians interested in endoscopic hemostasis. Although BPEC and heater probe are the two primary forms of thermal endoscopic treatment used at present, this trial by Hui et al. is the first study published in full manuscript form comparing the two modalities. The authors did not require clinical criteria of major bleeding for entry into the trial, but they did include only patients with active bleeding at endoscopy-probably the most important single predictor of further bleeding and a poor prognosis. Thus, Hui et al. appropriately selected only high-risk patients for their trial. This prospective study showed no significant differences among the three thermal treatments in any of the outcome parameters. The only major difference among the three groups was in the cost of the endoscopic treatment per patient, which was three to four times higher in the laser-treated group. Jensen et al. have presented two trials in abstract form comparing BPEC and heater probe. In the first they reported that the heater probe, but not BPEC, was significantly better than no endoscopic therapy (Gastroenterology 1988;94:A208). However, after they changed their BPEC technique (lower watt setting, prolonged period of coagulation) their results with BPEC improved dramatically (Gastrointest Endosc 1989;35:181; Gastrointest Endosc 1990;36:S38-S41). In a more recent abstract, Jensen et al. reported significantly better results with BPEC than with heater probe (Gastroenterology 1991;100:A92); however, because the patients in the heater probe group were significantly sicker at the time of randomization, the authors concluded that BPEC and heater probe were probably comparable. Coupled with the two abstracts by Jensen et al., the results of the study by Hui et al. suggest that BPEC and heater probe should be considered comparable in the treatment of bleeding ulcers. Although YAG laser was similar in efficacy in the present study, a number of factors make it a secondary choice for the treatment of bleeding ulcers. Laser units are extremely expensive, and in the past they were not portable. In addition, YAG lasers cause greater tissue injury than BPEC or heater probe and also require greater technical expertise. On the other hand, injection therapy should be considered on par with BPEC and heater probe. Numerous controlled studies have confirmed the efficacy of injection therapy, and recent comparisons with BPEC (Gastroenterology 1990;99:1303-1306; Gastrointest Endosc 1991;37:295-298) and heater probe (Gastroenter-
ology 1991;100:33-37) have indicated that injection therapy is comparable to these thermal methods. L. LAINE,M.D.
DOES THE TIME OF THE MONTH AFFECT THE FUNCTION OF THE GUT? McBurney M (Department of Foods and Nutrition, University of Alberta, Edmonton, Alberta, Canada). Starch malabsorption and stool excretion are influenced by the menstrual cycle in women consuming low-fibre western diets. &and J Gastroenterol 1991;26:880-886. Although most hormones are either named for or commonly associated with the particular function that was first noted by investigators, it is now clear that all hormones have a wide range of activities. The hormones related to the menstrual cycle have a surprising spectrum of gastrointestinal effects, including gallbladder contraction (Gastroenterology 1982;82:711-719), lower esophageal sphincter pressure (Gastroenterology 1976;71:232-234), and gut motility. Wald et al. (Gastroenterology 1981; 80:1497-1500) showed that gastrointestinal transit time to the cecum was prolonged during the luteal phase of the menstrual cycle. Lanson (Gastroenterology 1985; 89:996-999) found a close parallel between delay in transit time and levels of progesterone during pregnancy. His data suggested that the constipation seen during the third trimester was related more to hormonal changes than to any direct pressure effect of the expanded uterus. In the current study, 10 normal women were studied during the follicular phase of the menstrual cycle (days 6-11) and again during the luteal phase (days 16-21). The women ate standard meals that were designed to approximate a typical low-fiber, western type of diet. The daily intake was 16% protein, 34% fat, and 50% carbohydrate with the total calories calculated to maintain normal weight and activity. Three-day stool collections were made at the end of each phase. The subjects were given 10 g of lactulose, and intestinal transit time was determined by noting the first change in the breath hydrogen levels. Two stool enzyme activity levels, mucinase‘and p-glucuronidase, were also determined during each phase. Stool wet and dry weights were significantly greater during the follicular phase. Stool nitrogen levels were also greater during the follicular phase. It was assumed that starch absorption was greater during the luteal phase. In contrast to the studies by Wald and others that showed a prolongation of transit time during the luteal phase, however, no difference in this parameter was seen in the present study. Stool enzyme activities (mucinase and p-glucuronidase) were also unchanged during both phases of the cycle. Comments.
The present study seems to clearly show differences in gut function during the two phases of the menstrual cycle. Differences in the quantity of starch delivered to the colon could account for these findings. Progesterone is elevated during the luteal phase and is known to promote smooth muscle relaxation. Therefore, the simplest explanation for these observations would be a prolongation of transit time with increased small bowel starch absorption during the luteal phase. In this study, however, the transit time was not shown to be different during the two phases. One way to explain this failure to show a difference in transit time (which has been reported by others) is to note that the breath hydrogen test, used in this study, records the effect of the “leading edge” of the lactulose column that reaches the cecum. It
March 1992
does not measure the mean transit time (MTT) of any material passing through the gut. The MTT can be determined but requires stool-marking techniques. Scheppach (Gastreonterology 1988;95: t549-15553, using a glucosidase inhibitor to study starch malabsorption, noted that the MTT can either decrease or increase when starch malabsorption is induced. This depends in part on whether the MTT was initially high or low. It is not possible to determine from the present study whether changes in gut motility during the two phases of the menstrual cycle account for the difference in stool output. A direct hormonal effect on digestion or absorption cannot be ruled out. If there is greater delivery of starch to the colon during the follicular phase, several mechanisms might contribute to the increase in stool weight. Starch degradation can lead to a greater osmotic effect. Fatty acids are produced, and these may be incorporated by bacteria, therefore increasing the stool load. Fatty acids may also have a direct effect on colon function. The present study is useful for documenting the difference in stool weight in the menstrual phases. It is of no help in explaining the observation.
SELECTED SUMMARIES
1085
The clinical importance of these observations is not clear. Fluctuation in bowel function during the menstrual cycle has been noted by many women, and those with inflammatory bowel disease sometimes report a significant increase in diarrhea during the follicular phase. Drugs that depend on bacterial action for their effect (e.g., sulfasalazine) might have different efficacies when the starch load to the colon varies. Almost nothing is known about the absorption and action of drugs taken at different times of the menstrual cycle. Epidemiological evidence suggests that colon neoplasia varies with starch ingestion. Perhaps starch delivery to the colon will also need to be considered. The implication of this study, which raises far more questions than it answers, is that physicians need to broaden their concept of what taking a “menstrual history” means. Although the names of hormones refer to sexual and gestational activities, their actions also include effects on the coelom.
J. SWEETING, M.D.
GASTROENTEROLOGY Vol. 102,No. 3
No significant differences were seen among the three therapies in terms of blood transfusions, length of hospital stay, rate of emergency surgery, or mortality.
Comment. Controlled clinical trials of YAG laser, heater probe, and BPEC have yielded mixed results. However, careful analysis of these trials does suggest that patients at high risk for persistent or recurrent bleeding (clinically significant hemorrhage and endoscopic evidence of active bleeding or an ulcer with a nonbleeding visible vessel) benefit from therapy with BPEC, heater probe, and probably YAG laser. The National Institute of Health Consensus Conference on Therapeutic Endoscopy and Bleeding Ulcers concluded that BPEC and heater (JAMA 1989;262:1369-1372) probe were the two most promising modalities for endoscopic hemostatic therapy and ranked YAG laser at a secondary level. In addition, studies in a canine model have indicated that BPEC and heater probe are the most effective and safest thermal methods for coagulation of bleeding arteries (Gastroenterology 1987;92:11011108).
The article by Hui et al. is an important one for physicians interested in endoscopic hemostasis. Although BPEC and heater probe are the two primary forms of thermal endoscopic treatment used at present, this trial by Hui et al. is the first study published in full manuscript form comparing the two modalities. The authors did not require clinical criteria of major bleeding for entry into the trial, but they did include only patients with active bleeding at endoscopy-probably the most important single predictor of further bleeding and a poor prognosis. Thus, Hui et al. appropriately selected only high-risk patients for their trial. This prospective study showed no significant differences among the three thermal treatments in any of the outcome parameters. The only major difference among the three groups was in the cost of the endoscopic treatment per patient, which was three to four times higher in the laser-treated group. Jensen et al. have presented two trials in abstract form comparing BPEC and heater probe. In the first they reported that the heater probe, but not BPEC, was significantly better than no endoscopic therapy (Gastroenterology 1988;94:A208). However, after they changed their BPEC technique (lower watt setting, prolonged period of coagulation) their results with BPEC improved dramatically (Gastrointest Endosc 1989;35:181; Gastrointest Endosc 1990;36:S38-S41). In a more recent abstract, Jensen et al. reported significantly better results with BPEC than with heater probe (Gastroenterology 1991;100:A92); however, because the patients in the heater probe group were significantly sicker at the time of randomization, the authors concluded that BPEC and heater probe were probably comparable. Coupled with the two abstracts by Jensen et al., the results of the study by Hui et al. suggest that BPEC and heater probe should be considered comparable in the treatment of bleeding ulcers. Although YAG laser was similar in efficacy in the present study, a number of factors make it a secondary choice for the treatment of bleeding ulcers. Laser units are extremely expensive, and in the past they were not portable. In addition, YAG lasers cause greater tissue injury than BPEC or heater probe and also require greater technical expertise. On the other hand, injection therapy should be considered on par with BPEC and heater probe. Numerous controlled studies have confirmed the efficacy of injection therapy, and recent comparisons with BPEC (Gastroenterology 1990;99:1303-1306; Gastrointest Endosc 1991;37:295-298) and heater probe (Gastroenter-
ology 1991;100:33-37) have indicated that injection therapy is comparable to these thermal methods. L. LAINE,M.D.
DOES THE TIME OF THE MONTH AFFECT THE FUNCTION OF THE GUT? McBurney M (Department of Foods and Nutrition, University of Alberta, Edmonton, Alberta, Canada). Starch malabsorption and stool excretion are influenced by the menstrual cycle in women consuming low-fibre western diets. &and J Gastroenterol 1991;26:880-886. Although most hormones are either named for or commonly associated with the particular function that was first noted by investigators, it is now clear that all hormones have a wide range of activities. The hormones related to the menstrual cycle have a surprising spectrum of gastrointestinal effects, including gallbladder contraction (Gastroenterology 1982;82:711-719), lower esophageal sphincter pressure (Gastroenterology 1976;71:232-234), and gut motility. Wald et al. (Gastroenterology 1981; 80:1497-1500) showed that gastrointestinal transit time to the cecum was prolonged during the luteal phase of the menstrual cycle. Lanson (Gastroenterology 1985; 89:996-999) found a close parallel between delay in transit time and levels of progesterone during pregnancy. His data suggested that the constipation seen during the third trimester was related more to hormonal changes than to any direct pressure effect of the expanded uterus. In the current study, 10 normal women were studied during the follicular phase of the menstrual cycle (days 6-11) and again during the luteal phase (days 16-21). The women ate standard meals that were designed to approximate a typical low-fiber, western type of diet. The daily intake was 16% protein, 34% fat, and 50% carbohydrate with the total calories calculated to maintain normal weight and activity. Three-day stool collections were made at the end of each phase. The subjects were given 10 g of lactulose, and intestinal transit time was determined by noting the first change in the breath hydrogen levels. Two stool enzyme activity levels, mucinase‘and p-glucuronidase, were also determined during each phase. Stool wet and dry weights were significantly greater during the follicular phase. Stool nitrogen levels were also greater during the follicular phase. It was assumed that starch absorption was greater during the luteal phase. In contrast to the studies by Wald and others that showed a prolongation of transit time during the luteal phase, however, no difference in this parameter was seen in the present study. Stool enzyme activities (mucinase and p-glucuronidase) were also unchanged during both phases of the cycle. Comments.
The present study seems to clearly show differences in gut function during the two phases of the menstrual cycle. Differences in the quantity of starch delivered to the colon could account for these findings. Progesterone is elevated during the luteal phase and is known to promote smooth muscle relaxation. Therefore, the simplest explanation for these observations would be a prolongation of transit time with increased small bowel starch absorption during the luteal phase. In this study, however, the transit time was not shown to be different during the two phases. One way to explain this failure to show a difference in transit time (which has been reported by others) is to note that the breath hydrogen test, used in this study, records the effect of the “leading edge” of the lactulose column that reaches the cecum. It
March 1992
does not measure the mean transit time (MTT) of any material passing through the gut. The MTT can be determined but requires stool-marking techniques. Scheppach (Gastreonterology 1988;95: t549-15553, using a glucosidase inhibitor to study starch malabsorption, noted that the MTT can either decrease or increase when starch malabsorption is induced. This depends in part on whether the MTT was initially high or low. It is not possible to determine from the present study whether changes in gut motility during the two phases of the menstrual cycle account for the difference in stool output. A direct hormonal effect on digestion or absorption cannot be ruled out. If there is greater delivery of starch to the colon during the follicular phase, several mechanisms might contribute to the increase in stool weight. Starch degradation can lead to a greater osmotic effect. Fatty acids are produced, and these may be incorporated by bacteria, therefore increasing the stool load. Fatty acids may also have a direct effect on colon function. The present study is useful for documenting the difference in stool weight in the menstrual phases. It is of no help in explaining the observation.
SELECTED SUMMARIES
1085
The clinical importance of these observations is not clear. Fluctuation in bowel function during the menstrual cycle has been noted by many women, and those with inflammatory bowel disease sometimes report a significant increase in diarrhea during the follicular phase. Drugs that depend on bacterial action for their effect (e.g., sulfasalazine) might have different efficacies when the starch load to the colon varies. Almost nothing is known about the absorption and action of drugs taken at different times of the menstrual cycle. Epidemiological evidence suggests that colon neoplasia varies with starch ingestion. Perhaps starch delivery to the colon will also need to be considered. The implication of this study, which raises far more questions than it answers, is that physicians need to broaden their concept of what taking a “menstrual history” means. Although the names of hormones refer to sexual and gestational activities, their actions also include effects on the coelom.
J. SWEETING, M.D.
