Understanding the Laxative Effects of Coffee

V Mehta et al. JPGN 2023; 76: 20-24. Open Access! Effect of Caffeine on Colonic Manometry in Children

Methods: A prospective study of pediatric patients (N=16) undergoing standard colonic motility testing that were able to consume caffeinated coffee, decaffeinated coffee, and caffeine tablet during colonic manometry (with normal response to bisacodyl)

Key findings:

  • Caffeinated coffee resulted in a higher AUC, motility index (MI), and time to HAPC compared with decaffeinated coffee (P < 0.05).
  • Urge to defecate, or actual bowel movement in 100% (n = 16) of patients after intraluminal bisacodyl (IB), compared to 81% (n = 13) after caffeinated coffee (CC), 56% (n= 9) after caffeine tablet (CT), and 50% (n = 8) after decaffeinated coffee (DC)
  • Based on AUC between T = 1 and T = 60 minutes after each agent, the response of the colon to IB was more robust, relative to other agents (P < 0.05). Both CC and DC had resulted in a higher AUC compared to CT (P < 0.05), but no significant difference between CC and DC 
  • Caffeine is indeed a colonic stimulant; however, other components of caffeinated and non-caffeinated beverages likely induce colonic response as well
  • Limitation: Study population: patients required motility testing for refractory chronic constipation Therefore, they do not represent a normal population

My take: As with adult patients, coffee (both caffeinated and decaffeinated) acts as a colonic stimulant. Though, it is relatively weak compared to bisacodyl

Related blog posts:

“Simple Remedies for Constipation”

“Common sense is not so common” –Voltaire

A useful review of constipation management in the NY Times: Simple Remedies for Constipation

This review explains the role of diet and exercise in treatment of constipation.  The author notes that coffee helps many and that laxatives are safe. In addition, the idea of “autointoxication” due to infrequent bowel movements is debunked.

Here’s an excerpt:

Dr. Wald and others say that properly designed studies of these [stimulatory] laxatives have shown no harm to the colon when they are taken in recommended amounts.

Yet many doctors still warn – inappropriately, Dr. Wald says — against taking stimulatory laxatives for more than a few days. Indeed, the website FamilyDoctor.org states, “When these laxatives are taken for a long time, the bowel can lose its muscle tone and ‘forget’ how to push the stool out on its own.” Best to forget this outdated idea as long as you stick to the recommended dose if you must take these products.

Related blog posts:

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Coffee and Caffeine Associated With Less Fibrosis Among Patients with Hepatitis C

Perhaps I need to start drinking coffee.  In the absence of smoking or alcohol, it is reported to have a number of benefits. A recent study (N Khalaf et al. Clin Gastroenterol Hepatol 2015; 13: 1521-31) found that a “modest daily caffeine intake (as little as 100 mg) may protect against advanced hepatic fibrosis in men with chronic HCV infection.” This cross-sectional study of veterans with chronic HCV looked at 910 patients.  Patients were divided into controls with mild fibrosis (F0-F3) based on FibroSURE compared with those with F3/F4-F4 advanced fibrosis.  FibroSURE estimates are based on an algorithm which incorporates α2-macroglobulin, apolipoprotein A1, haptoglobin, total bilirubin, γ-glutamyl -transpeptidase, and alanine amiontransferase. Key findings:

  • Caffeinated coffee was higher among controls than those with advanced fibrosis (1.37 vs 1.05 cups/d, P=.038)
  • Overall caffeine ingestion was also higher in the controls; 66% of controls consumed >100 mg/day compared with 58% of those with advanced fibrosis.

Limitation: observaitonal, retrospective study with self-reported coffee/caffeine consumption. Related blog posts:

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Good News for Starbucks & Coffee Vendors

This blog has posted a number of favorable reports on coffee, even though I’m not a coffee enthusiast.  In general, coffee has favorable health effects when it is not paired with alcohol or tobacco.

A recent coffee study (Gastroenterol 2015; 148: 118-25) shows an association between coffee intake and reduced incidence of liver cancer and death from chronic liver disease in the U.S.

Here’s a link to a summary of the article: GastroHepNews Coffee and Liver Disease

  • During an 18-year follow-up period, there were 451 incident cases of hepatocellular carcinoma and 654 deaths from chronic liver disease.
  • Compared with non-coffee drinkers, the researchers noted that those who drank 2–3 cups per day had a 38% reduction in risk for hepatocellular carcinoma.
  • Those who drank ≥4 cups per day had a 41% reduction in hepatocellular carcinoma risk.
  • Compared with non-coffee drinkers, participants who consumed 2–3 cups coffee per day had a 46% reduction in risk of death from chronic liver disease, and those who drank ≥4 cups per day had a 71% reduction.
  • The inverse associations were similar regardless of the participants’ ethnicity, sex, body mass index, smoking status, alcohol intake, or diabetes status.

Related blog posts:

More liver-related news: Man with infected hepatitis C sentenced to 3 years for spitting in officer’s face (from The Republic/AP News)

Does Anyone Know Why This Toilet is in our Parking Garage?

Does Anyone Know Why This Toilet is in our Office Parking Garage?

Hepatology Update -Summer 2014

Preventing Perinatal Transmission of Hepatitis B Virus (HBV): Hepatology 2014; 60: 468-76.  This nonrandomized study, conducted between 2009-2011 with approximately 700 patients, showed that the rate of perinatal transmission of can be brought down almost to zero by instituting therapy with either telbivudine or lamivudine in the third trimester of pregnancy.  The accompanying editorial (pgs 448-51) indicates that either telbivudine or tenofovir (both pregnancy class B agents with regard to teratogenicity) are preferred agents due to higher barrier to resistance. And, the article suggests starting as early as week 28 (especially if high viral HBV DNA load) and no later than 32 weeks gestation. Other recommendations from editorial include stopping antiviral after delivery in women who intend to breastfeed.

More on coffee: Hepatology 2014; 60: 661-69.  Coffee but not tea conferred protection from cirrhosis mortality.  “Compared to non-daily coffee drinkers, those who drank two or more cups per day had a 66% reduction in mortality risk.”  This study also had an accompanying editorial (pg 464-67) which reviews the biologic plausibility and potential mechanisms.

NASH pathology: Hepatology 2014; 60: 565-75.  The study describes a more precise way to categorize the diagnosis of nonalcoholic steatohepatitis (NASH) using the European Fatty Liver Inhibition of Progression (FLIP) pathology consortium proposal.  The diagnosis of NASH requires the presence of ballooning and lobular inflammation in addition to steatosis.  Using the FLIP approach, diagnosis concordance increased significantly.

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Live longer -drink more coffee

In a previous post, I was impressed with some of the benefits of coffee (Drink Up!).  More good news for coffee drinkers: drinking coffee is associated with decreased mortality (NEJM 2012; 366: 1891-1904).  Full disclosure –I don’t even drink coffee & I am not being paid by industry!

This study examined a huge population, 5,148,760 person-years (1995-2008) among 229,119 men and 173,141 women in the NIH-AARP Diet and Health Study with participants aged 50-71 at baseline.  With age-adjusted models, if adjusted for smoking, an inverse association between coffee consumption and mortality was noted.  With 6 cups per day, the hazard ratio (HR) was 0.90 for men and 0.85 for women.  For 2-3 cups, the HRs were 0.94 and 0.95 respectively.

Declines in mortality were noted for heart disease, respiratory disease, stroke, injuries/accidents, diabetes and infections, but not for deaths from cancer.  However, while coffee is associated with improved mortality data, a causal role for coffee consumption in reducing mortality cannot be established with this study.

Related link:


Drink Up!

Green tea and coffee have a lot of advocates and a number of articles suggest that each can have beneficial effects for the liver.  This month’s Hepatology describes how a green tea component, epigallocatechin-3-gallate (EGCG), inhibits hepatitis C viral (HCV) entry. ECGC acts by blocking viral attachment to target cells with all HCV genotypes; it does not affect viral replication.  Other components of green tea do not have this effect.  A complete description of green tea components is described in the discussion of the article, Hepatology 2012: 54: 1947-55.  Also, there have been preliminary dosing studies in healthy volunteers which have shown that EGCG is safe at doses of 800mg daily for four weeks.  This would be the equivalent of drinking 8-16 cups of green tea per day (Clin Cancer Res 2003; 9: 3312-19).  In order to eliminate HCV, however, even higher amounts of EGCG would be likely.


Coffee also has been studied and has been associated with decreasing liver fibrosis.  In addition, coffee may enhance response to HCV treatments.  To my knowledge, there have not been extensive studies of either coffee or green tea for pediatric patients.

Additional References:

  • -Gastroenterology 2011; 140: 1961. Coffee (3 cups/day) increases response to PEG/RBV in HCV
  • -Hepatology 2009; 51: 201. Coffee decreases fibrosis. n=177.
  • -Hepatology 2009; 50: 1360. Coffee intake associated with slower progression of HCV liver disease
  • -Hepatology 2009; 50: 970. Coffee -2 cups per day decreases risk of liver fibrosis & HCC. Coffee has methylxanthin which inhibits connective tissue growth factor.