Arnold Wald

Myths and Misconceptions About Chronic Constipation

There are many strongly held beliefs about constipation that are not evidence based. The purpose of this review is to address these beliefs concerning various aspects of constipation. There is no evidence to support the theory that diseases may arise via “autointoxication,” whereby poisonous substances from stools within the colon are absorbed. Dolichocolon, defined as an elongated colon, should not be seen as a cause of constipation. The role of sex hormones altering gut function during the menstrual cycle appears to be minimal. During pregnancy they may play a role in slowing gut transit. Hypothyroidism can cause constipation, but among patients presenting with constipation, hypothyroidism is rare. A diet poor in fiber should not be assumed to be the cause of chronic constipation. Some patients may be helped by a fiber-rich diet but many patients with more severe constipation get worse symptoms when increasing dietary fiber intake. There is no evidence that constipation can successfully be treated by increasing fluid intake unless there is evidence of dehydration. In the elderly constipation may correlate with decreased physical activity, but many cofactors are likely to play a role. Intervention programs to increase physical activity as part of a broad rehabilitation program may help. It is unlikely that stimulant laxatives at recommended doses are harmful to the colon. A proportion of patients with chronic constipation is dependent of laxatives to achieve satisfactory bowel function, but this is not the result of prior laxative intake. Tolerance to stimulant laxatives is uncommon. There is no indication for the occurrence of “rebound constipation” after stopping laxative intake. While laxatives may be misused, there is no potential for addiction.

Influence of gender and menopause on gastric emptying and motility

The aims of this study were to determine (a) if there are differences in gastric emptying rates of a mixed liquid and solid meal between men and women, (b) if menopausal status affects gastric emptying, and (c) whether differences in solid emptying rates are associated with alterations in postprandial antral motility parameters. A dual-isotope technique was used to measure gastric emptying in 20 men, 18 premenopausal women, 14 postmenopausal women, and 8 postmenopausal women taking estrogen and progesterone hormone replacement. A multilumen perfusion catheter was used to measure antral motility in 6 men and 6 premenopausal women. Premenopausal women, postmenopausal women, and postmenopausal women taking oral estrogen and progesterone had slower gastric emptying of liquids than did men (p less than 0.025, less than 0.05, and less than 0.025, respectively). Both premenopausal women and postmenopausal women taking sex hormone replacement therapy had slower emptying of solids than did men (p less than 0.025 and less than 0.05) but, in contrast to liquids, postmenopausal women not on hormone replacement emptied solids at a rate similar to that of men. There were no differences in postprandial antral motility parameters between men and premenopausal women. These findings support the hypothesis that sex steroid hormones have variable inhibitory effects on gastric emptying of a mixed meal and this should be considered when studying gastric emptying in disorders that occur predominantly in premenopausal women.

The burden of constipation on quality of life: results of a multinational survey

Background The impact of constipation on quality of life (QoL) may vary in different cultural or national settings.

Treatment options for fecal incontinence

PURPOSE: Fecal incontinence is a socially devastating disorder which affects at least 2.2 percent of community dwelling adults and 45 percent of nursing home residents. Most incontinent patients can be helped, but physicians are poorly informed about treatment options. The aim of this study was to develop a consensus on treatment options by convening a conference of surgeons, gastroenterologists, nurses, psychologists, and patient advocates. METHOD: A 1–1/2 day conference was held in April, 1999. Experts from different disciplines gave overviews, followed by extended discussions. Consensus statements were developed at the end of the conference. This summary statement was drafted, circulated to all participants, and revised based on their input. CONCLUSIONS: 1) Diarrhea is the most common aggravating factor for fecal incontinence, and antidiarrheal medications such as loperamide and diphenoxylate or bile acid binders may help. Fecal impaction, a common cause of fecal incontinence in children and elderly patients, responds to combinations of laxatives, education, and habit training in approximately 60 percent. These causes of fecal incontinence can usually be identified by history and physical examination alone. 2) In patients who fail medical management or have evidence of sphincter weakness, anorectal manometry and endoanal ultrasound are recommended as helpful in differentiating simple morphologic defects from afferent and efferent nerve injuries and from combined structural and neurologic injuries. 3) Biofeedback is a harmless and inexpensive treatment which benefits approximately 75 percent of patients but cures only about 50 percent. It may be most appropriate when there is neurologic injury (i.e., partial denervation), but it has been reported to also benefit incontinent patients with minor structural defects. 4) External anal sphincter plication with or without pelvic floor repair is indicated when there is a known, repairable structural defect without significant neurologic injury. It is effective in approximately 68 percent. 5) Salvage operations are reserved for patients who can not benefit from biofeedback or levator-sphincteroplasty. These include electrically stimulated gracilis muscle transpositions and colostomy. 6) Antegrade enemas delivered through stomas in the cecum or descending colon reduce or eliminate soiling in approximately 78 percent of children with myelomeningocele; this operation may come to be more widely applied. 7) Investigational treatments include implanted nerve stimulators, artificial sphincters, and anal plugs. 8) Patient characteristics which influence choice of treatment include mental status, mobility impairment, and typical bowel habits. 9) Additional research is needed to better define the mechanisms responsible for fecal incontinence, to assess the efficacy of these treatments, to develop better treatments for nursing home residents, and to identify predictors of outcome.

Effect of tegaserod in chronic constipation: a randomized, double-blind, controlled trial.

BACKGROUND AND AIMS Chronic constipation is a common gastrointestinal disorder. The aim of this study was to evaluate the efficacy, safety, and tolerability of tegaserod, a serotonin subtype 4 receptor partial agonist in patients with chronic constipation. METHODS This was a randomized, double-blind, placebo-controlled study. After a 2-week baseline, patients received tegaserod 2 mg twice daily (n = 450), tegaserod 6 mg twice daily (n = 451), or placebo (n = 447) for 12 weeks, followed by a 4-week withdrawal period. Responders were those patients having been treated for at least 7 days with an increase of > or =1 complete spontaneous bowel movement/week vs. baseline during weeks 1-4 (primary variable) and weeks 1-12 (secondary variable). Other secondary variables included patient assessment of constipation symptoms (number of bowel movements, stool form, abdominal bloating/distention, straining, and abdominal pain/discomfort), and global assessment of constipation and bowel habits. RESULTS Responder rates for complete spontaneous bowel movement during weeks 1-4 were significantly greater ( P < 0.0001) in the tegaserod 2 mg twice daily (41.4%) and 6 mg twice daily groups (43.2%) vs. placebo (25.1%). This effect was maintained over 12 weeks. Statistically significant improvements over placebo were observed across the majority of secondary variables for both tegaserod doses. No rebound effect was observed after treatment withdrawal. Tegaserod was well tolerated; headache and nasopharyngitis, the most frequent adverse events, were more common in the placebo group than in either tegaserod group. CONCLUSIONS Over 12 weeks, tegaserod treatment produced significant improvements in chronic constipation symptoms and was also safe and well tolerated.

Prevalence of bowel dysfunction in multiple sclerosis: A population survey

An unselected outpatient population of 280 individuals with multiple sclerosis was surveyed to determine the prevalence of bowel dysfunction and to define their characteristics and their relationship to the nongastrointestinal manifestations of the disease. Constipation was present in 43%, was similar in frequency in both sexes, and was more common in patients, regardless of degree of disability, than in a control population. Frequency of constipation also correlated with duration of disease and genitourinary symptoms but did not correlate with use of any medications in mildly disabled patients. Fecal incontinence had occurred at least once in the preceding 3 mo in 51% of patients and once per week or more frequently in 25% of patients who were questioned in more detail with a follow-up questionnaire. Correlations of fecal incontinence with disability, duration of disease, and presence of genitourinary symptoms were similar to constipation. The prevalence of bowel dysfunction (constipation and/or fecal incontinence) in the multiple sclerosis population was 68%, and this manifestation was common even in mildly disabled subjects. Bowel dysfunction can be a source of considerable ongoing social disability in patients with multiple sclerosis. Further studies are needed to characterize the pathophysiology of this common disorder so that effective therapeutic strategies can be identified.

American Neurogastroenterology and Motility Society consensus statement on intraluminal measurement of gastrointestinal and colonic motility in clinical practice

Abstract  Tests of gastric, small intestinal and colonic motor function provide relevant physiological information and are useful for diagnosing and guiding the management of dysmotilities. Intraluminal pressure measurements may include concurrent measurements of transit or intraluminal pH. A consensus statement was developed and based on reports in the literature, experience of the authors, and discussions conducted under the auspices of the American Neurogastroenterology and Motility Society in 2008. The article reviews the indications, methods, performance characteristics, and clinical utility of intraluminal measurements of pressure activity and tone in the stomach, small bowel and colon in humans. Gastric and small bowel motor function can be measured by intraluminal manometry, which may identify patterns suggestive of myopathy, neuropathy, or obstruction. Manometry may be most helpful when it is normal. Combined wireless pressure and pH capsules provide information on the amplitude of contractions as they traverse the stomach and small intestine. In the colon, manometry assesses colonic phasic pressure activity while a barostat assesses tone, compliance, and phasic pressure activity. The utility of colonic pressure measurements by a single sensor in wireless pressure/pH capsules is not established. In children with intractable constipation, colonic phasic pressure measurements can identify patterns suggestive of neuropathy and predict success of antegrade enemas via cecostomy. In adults, these assessments may be used to document severe motor dysfunction (colonic inertia) prior to colectomy. Thus, intraluminal pressure measurements may contribute to the management of patients with disorders of gastrointestinal and colonic motility.

Effect of pregnancy on gastrointestinal transit.

In order to evaluate the possible effects of pregnancy-associated sex steroids on gastrointestinal function, we determined gastrointestinal transit times and sex steroid levels in 15 women during the third trimester of their pregnancies and again 4–6 weeks following delivery when gastrointestinal function had symptomatically returned to normal. Gastrointestinal transit time from ingestion of a liquid lactulose meal to its delivery to the cecum was determined by monitoring breath hydrogen concentrations at 10-min intervals. Gastrointestinal transit times were significantly prolonged in the third trimester of pregnancy, when progesterone and estradiol levels were increased, compared to the postpartum period. This study supports previous findings which suggest that increasing levels of progesterone and estradiol affect gastrointestinal function and therefore may contribute to gastrointestinal symptoms that often occur in pregnant women.

A multinational survey of prevalence and patterns of laxative use among adults with self‐defined constipation

Background  While numerous studies report prevalence of constipation, use of laxatives is poorly understood.

Psychological and physiological characteristics of patients with severe idiopathic constipation

This study prospectively evaluated psychological profiles and selected parameters of colonic and anorectal sensorimotor function in 25 consecutive patients who were referred for severe idiopathic constipation. Measurement of colonic transit of radiopaque markers divided patients into those with normal transit (n = 10) and those with slow transit (n = 15). As measured by the Hopkins Symptom Checklist, patients with normal transit constipation demonstrated significantly higher scores for psychological distress in the global symptoms index and nine clinical subscales than did those with slow transit constipation and gastrointestinal control subjects (n = 25). Both groups with constipation had decreased rectal sensation compared with controls but there was no relationship to rectal compliance or threshold of internal sphincter relaxation. There was also no relation between abnormalities of anorectal parameters, including expulsion dynamics, and psychological profiles in two groups. Measurement of colonic transit and psychological profiles in patients with severe idiopathic constipation identify two groups of patients with respect to possible pathogenesis of symptoms. Accordingly, different therapeutic approaches may be required, one behaviourally and psychologically based and the other focused on the possible modification of disordered colonic transit.