Tea consumption: a cause of constipation?

Abstract

Uncontrolled clinical observations in our outpatient clinic suggested that severe constipation in young adults was related to tea consumption of one to two litres daily. We have therefore carried out a study on healthy volunteers. Subjects, methods, and resultsTwelve healthy volunteers aged [23][24][25][26][27][28][29][30] years participated in the study, which comprised two test periods of seven days. Diet decreased from 436 to 310 iLmol/24 h (p<005) during the tea period, whereas faecal mass showed only a slight and non-significant reduction.Specific gravity of urine increased from 1014 to 1017 g/l (p<005) in the tea period, and urine oxalate excretion rose from 0-36 to 0-41 mmol (3-2 to 3-7 mg)/24 h (p <0 10); the urine volume showed only a slight non-significant increase. During the tea period the following mean plasma concentrations were increased (p<0 05): albumin from 599 to 623 imol/l (4-13 to 4 30 g/ 100 ml); creatinine from 73 to 82 ,tmol/l (826 to 927 Zg/ 100 ml); urate from 0-27 to 0-29 mmol/l (4-5 to 4-8 mg/100 ml); sodium from 128 to 133 mmol (mEq)/l; potassium from 3-5 to 3-8 mmol (mEq)/l; and calcium from 1-97 to 2-11 mmol/l (7-8 to 8-4 mg/100 ml). No changes were seen in carbamide, haemoglobin, or phosphate values. There was no change in body weight. CommentThe effect of tea was probably due to theophylline, which (presumably via the kidneys) causes extracellular dehydration, a secondary increase in intestinal fluid absorption, and hence constipation. This hypothesis agrees with the findings in a study of constipating cocoa products.3 The estimated daily intake of theophylline with tea in our study was roughly 100 ±mol,4 sufficient to increase the renal glomerular filtration rate and decrease tubular reabsorption.5 The raised plasma concentrations of various components and the increased intestinal transit time during the tea period support the hypotheses of dehydration and constipation.We suggest that the relation between fluid consumption and intestinal transit time should be considered in studies evaluating the influence of compounds-for example, dietary fibres and drugs-on intestinal function. Pseudomembranous colitis after treatment with metronidazole Pseudomembranous colitis is a rare condition that may complicate the administration of certain antimicrobial agents. The most common of the many antibiotics that have been implicated are lincomycin and clindamycin. We report a case that followed a short course of intrarectal metronidazole used prophylactically in a patient undergoing emergency appendicectomy. To our knowledge there has been no recorded case of the condition in association with metronidazole alone. This has important implications as metronidazole has been suggested as a therapeutic agent to treat this condition. Case reportA 13-year-old girl was admitted with a history of abdominal pain. Acute appendicitis was diagnosed and appendicectomy was performed. Histological examination showed early focal appendicitis. She was given prophylactic metronidazole rectally 1 g before operat...

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“…Tea was hypothesized to exert a constipating effect through a theophylline-mediated (a metabolite from caffeine), extracellular dehydration. 19 On the other hand, a stimulating effect of tea on GI motility has also been reported. 20 Therefore, in our study caffeinecontaining tea was excluded.…”

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Effect of black tea drinking on blood lipids, blood pressure and aspects of bowel habit

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