The digestive tract runs from the place where the food comes in to the other place where the waste is emitted. The range of afflictions, temporary disturbances, and diseases of serious concern is very large, and going into detail on some of the specific diseases is well beyond the scope of this missive. What I hope to be able to manage is a good look at the overall picture, and, most important, what we can do to keep our digestive system – and ourselves! – in as good shape as possible.
The prevalence of digestive diseases, as reported by National Institute of Diabetes and Digestive and Kidney Diseases, is quite high. This is not surprising, considering what we require our digestive system to accomplish every day and almost every hour of the day. The reported prevalence in the US is 60 to 70 million individuals affected by all digestive diseases, and 48.3 million ambulatory care visits, consisting of 36.6 million office visits, 7.9 million hospital emergency department visits, and 3.8 million outpatient department visits. Those statistics are not current, dating from 2010, but they are the most recent I could find.
There were 21.7 million hospitalizations due to digestive diseases, and (in 2009) 246,931 deaths. In 2007, 12% of all inpatient hospital procedures, including both diagnostic and therapeutic inpatient procedures, amounting to 5.4 million procedures, were due to digestive diseases. And 20% of all ambulatory surgical procedures – meaning that the patient walked into a hospital and was found to require surgery – were due to a digestive disease.
The costs (and this is data going back to 2004) were also quite high – a total of $141.8 billion, consisting of $97.8 billion in direct medical costs and $44 billion in indirect costs such as disability and what they refer to as “mortality costs.”
Here, for your further detailed information, is a list of the sixteen diseases/ailments as compiled by that above-named National Institute. You can give it a quick once-over – I will discuss some of these in more detail.
Abdominal Wall HerniaAmbulatory care visits: 3.6 million (2009)Surgical procedures: 526,000 (2006) (inguinal hernia only)Hospitalizations: 380,000 (2010)Mortality: 1,322 deaths (2010)Prescriptions: 3.7 million (2004)
Chronic ConstipationPrevalence: 63 million people (2000)Ambulatory care visits: 4.0 million (2009)Hospitalizations: 1.1 million (2010)Mortality: 132 deaths (2010)Prescriptions: 5.3 million (2004)
Diverticular DiseasePrevalence: 2.2 million people (1998)Ambulatory care visits: 2.7 million (2009)Hospitalizations: 814,000 (2010)Mortality: 2,889 deaths (2010)Prescriptions: 2.8 million (2004)
GallstonesPrevalence: 20 million people (2004)Ambulatory care visits: 2.2 million (2006–2007) (includes all disorders of the gallbladder and biliary tract)Surgical procedures: 503,000 (2006) (laparoscopic cholecystectomies only)Hospitalizations: 675,000 (2010)Mortality: 994 deaths (2010)Prescriptions: 1.65 million (2004)
Gastroesophageal Reflux DiseasePrevalence: Reflux symptoms at least weekly: 20 percent of the population (2004)Ambulatory care visits: 8.9 million (2009)Hospitalizations: 4.7 million (2010)Mortality: 1,653 deaths (2010)Prescriptions: 64.6 million (2004)
Gastrointestinal InfectionsPrevalence: Non-foodborne gastroenteritis: 135 million people (1998)Foodborne illness: 76 million people (1998)Ambulatory care visits: 2.3 million (2004)Hospitalizations: 487,000 (2010)Mortality: 11,022 deaths (2011)Prescriptions: 938,000 (2004)
HemorrhoidsPrevalence: 75 percent of people older than 45 (2006)Ambulatory care visits: 1.1 million (2009)Hospitalizations: 266,000 (2010)Mortality: 20 deaths (2010)Prescriptions: 2 million (2004)
Inflammatory Bowel DiseaseAmbulatory care visits: 1.9 million (2009)
Crohn’s DiseasePrevalence: 359,000 people (1998)Ambulatory care visits: 1.1 million (2004)Hospitalizations: 187,000 (2010)Mortality: 611 deaths (2010)Prescriptions: 1.8 million (2004)
Ulcerative ColitisPrevalence: 619,000 people (1998)Ambulatory care visits: 716,000 (2004)Hospitalizations: 107,000 (2010)Mortality: 305 deaths (2010)Prescriptions: 2.1 million (2004)
Irritable Bowel SyndromePrevalence: 15.3 million people (1998)Ambulatory care visits: 1.6 million (2009)Hospitalizations: 280,000 (2010)Mortality: 21 deaths (2010)Prescriptions: 5.9 million (2004)
Liver DiseasePrevalence: 3.0 million people (2011)Ambulatory care visits: 635,000 (2009) (cirrhosis only)Procedures: 6,342 (2011) (liver transplants)Hospitalizations: 1.2 million (2010)Mortality: 42,923 deaths (2010)Prescriptions: 731,000 (2004)
PancreatitisPrevalence: 1.1 million people (1998)Incidence: Acute: 17 cases per 100,000 people (2003); chronic: 8.2 cases per 100,000 people (1981)Ambulatory care visits: 881,000 (2004)Hospitalizations: 553,000 (2010)Mortality: 3,413 deaths (2010)Prescriptions: 766,000 (2004)8
Peptic Ulcer DiseasePrevalence: 15.5 million people (2011)Ambulatory care visits: 669,000 (2006–2007)Hospitalizations: 358,000 (2010)Mortality: 2,981 deaths (2011)Prescriptions: 5 million (2004)
Viral Hepatitis APrevalence of chronic infection: None (2007)Incidence: 1,670 new acute clinical cases (2010)Ambulatory care visits: Infrequent (2004)Hospitalizations: 10,000 (2004)Mortality: 29 deaths (2010)
Viral Hepatitis BPrevalence of chronic infection: 800,000 to 1.4 million people (2007)Incidence: 3,350 new acute clinical cases (2010)Ambulatory care visits: 729,000 (2004)Hospitalizations: 61,000 (2010)Mortality: 588 deaths (2010)
Viral Hepatitis CPrevalence of chronic infection: 2.7 to 3.9 million people (2007)Incidence: 850 new acute clinical cases (2010)Ambulatory care visits: 1.2 million (2009)Hospitalizations: 419,000 (2010)Mortality: 6,844 deaths (2010)
To compile the statistics that I quoted above, The National Institute gathered data from 29 different sources, none more recent than 2010. Obviously, those statistics have changed in the intervening 15 years, but I have found nothing (or nothing substantial) any more recent. Looking at those statistics, we can arrive at some general conclusions.
In terms of prevalence, the most common digestive malady is non-foodborne gastroenteritis, which affected 135 million people in 1998. Gastroenteritis describes pain and inflammation in the stomach and intestines, leading to vomiting and diarrhea. Ordinary indigestion can be classified as gastroenteritis, but in this case the reference is to symptoms not caused by food, but by pathogens – bacteria or viruses. Of course, these mostly enter our digestive systems carried by things we eat, but often it’s not the food that brings on that particular illness, it’s those malicious pathogens.
As you may have noticed from those statistics, in addition to the 135 million people who got non-food-borne gastroenteritis, 76 million did get it from food. In all, gastroenteritis was the cause of 2.3 million hospital outpatient visits, 487,000 hospitalizations, and 11,022 deaths.
Looking at prevalence data configured in different ways, we find that a great many people experience constipation occasionally. Chronic constipation affected 63 million people in the year 2000; however, the consequences are not especially menacing. Even though there were 1.1 million hospitalizations, the condition resulted in 132 deaths, which is a very small number, especially when compared with the death rates from some other diseases of the digestive tract.
The digestive maladies with the lowest mortality figures are hemorrhoids, which accounted for 20 deaths in 2010; irritable bowel syndrome, tagged with 21 deaths; and hepatitis A, the cause of 29 deaths. It’s not obvious how hemorrhoids could directly be a cause of death, but they can become infected and lead to a more general infection in the lower colon.
A closer look at some specific diseases of the intestinal tract
The disease with the highest mortality was liver disease, which was the cause of death of 51,643 persons in 2020 in the US, according to the CDC. No other malady came close. Globally, liver disease accounts for about two million deaths annually and is responsible for 4% of all deaths (1 out of every 25 deaths worldwide); approximately two-thirds of all liver-related deaths occur in men.
Liver disease was followed, as noted above, by gastrointestinal infections with 11,022 deaths, hepatitis C (6,844 deaths), peptic ulcers (2,981 deaths), and diverticular disease (2,889 deaths).
I should interject that I find “cause of death” statistics somewhat baffling. In some cases, the cause of death is quite evident. I should not need to go into detail as to the diseases that directly result in the patient’s death, such as cardiovascular diseases, cancers, and others. But in many cases, assigning a cause of death is a decision by hospital attending physicians. For example, the diverticulum is a pouch or sac growing (diverging) from the wall of the colon. Small particles of whatever is passing through the colon can get stuck in that little pouch. Instead of being ejected in the normal way through the rectum, they lodge in the diverticulum, providing a nest for the pathogens that are present in the digestive waste to multiply and cause serious infections. Those serious infections would be the cause of death noted above.
A 17-year study by Mass General Hospital found that 55,096 of 44,915,066 deaths during that study period (0.12%) were reported to be caused by diverticulitis. Approximately 68% of diverticulitis deaths were in women vs. 32% in men. Deaths from diverticulitis comprised 0.017% of all deaths in women and 0.08% in men (P<0.001). According to my calculations, that works out to 3,241 deaths annually, which is not too far off from the 2,889 annual deaths reported in the National Institute of Diabetes and Digestive and Kidney Diseases data.
Returning, for a moment, to the subject of liver disease, we should understand what a colossal amount of work our livers perform. Every drop of the blood leaving the stomach and intestines passes through our livers. The liver processes this blood and balances the essential nutrients conveyed in the blood. It also metabolizes pharmaceuticals into forms that are easier to use for the rest of the body. Sometimes these pharmaceuticals are ingested in forms that have toxic qualities, but our livers process these agents and make them non- toxic. More than 500 vital functions have been identified with the liver. Among them are:
Production of bile, which helps carry away waste and break down fats in the small intestine during digestion
Production of certain proteins for blood plasma
Production of cholesterol and special proteins to help carry fats through the body
Conversion of excess glucose into glycogen for storage (glycogen can later be converted back to glucose for energy) and to balance and make glucose as needed
Regulation of blood levels of amino acids, which form the building blocks of proteins
Processing of hemoglobin in the blood for use of its iron content (the liver stores iron)
Conversion of poisonous ammonia to urea (urea is an end product of protein metabolism and is excreted in the urine)
Clearing the blood of harmful drugs and other poisonous substances
Regulating blood clotting
Resisting infections by making immune factors and removing bacteria from the bloodstream
Clearance of bilirubin, also from red blood cells. If there is an accumulation of bilirubin, the skin and eyes turn yellow.
When the liver breaks down harmful substances, the by-products are excreted into the bile or blood. Bile by-products enter the intestine and leave the body in the form of feces. Blood by-products are filtered out by the kidneys, and leave the body in the form of urine.
Liver failure, sometimes leading to liver transplants, can have a range of different causes. A frequent cause is cirrhosis, commonly caused by excessive alcohol consumption, but sometimes also a consequence of viral hepatitis. A cause of liver failure which has increased in frequency recently is overdoses of acetaminophen, most commonly known as Tylenol. Most of these acetaminophen overdoses are entirely involuntary – people do not binge on Tylenol. But acetaminophen is sometimes compounded with oxycodone, which is sold under several brand names.
Some individuals have become addicted to oxycodone. Oxycodone is a semi-synthetic pain-killer which has narcotic properties. It has been a popular drug of abuse among the narcotic abusing population. Some of the street names are Hillbilly Heroin, Kicker, OC, Ox, and Perc, short for Percocet, one of the brand names.
The physiological effects of oxycodone include pain relief, sedation, respiratory depression, constipation, papillary constriction, and cough suppression. Euphoria and feelings of relaxation are the most common effects of oxycodone on the brain, which explains its high potential for abuse.
The effects of an overdose include extreme drowsiness, muscle weakness, confusion, cold and clammy skin, pinpoint pupils, shallow breathing, slow heart rate, fainting, coma, and, sometimes, death. I have not been able to pin down any specific data on the number of deaths related to oxycodone overdoses, but overall drug overdose deaths involving prescription opioids rose from 3,442 in 1999 to 17,029 in 2017, and then from 2017 to 2023, there was an overall decline to 13,026 deaths.
Medically, it is used to treat severe pain that does not respond to other analgesics. When a person takes excessive quantities of oxycodone compounded with acetaminophen, he/she is ingesting excessive quantities of acetaminophen, which is particularly toxic to the liver when consumed with excessive alcohol. And taking excessive amounts of this combination appears to go hand in hand with heavy drinking. As a result, individuals who overindulge in those two substances are at high risk of severe liver damage. It has been estimated by some observers that the combination of oxycodone/acetaminophen in amounts greater than prescribed or recommended, along with a considerable amount of booze, is the single largestfactor that leads to the need for liver transplants.
In 2023, 10,660 liver transplants were performed in the US, more than ever recorded in a single year. Obviously, liver transplants are impossible without the availability of viable, relatively healthy livers. Organ donors, no matter how public-spirited and attuned to the common good, do not donate their livers, so livers for transplantation can only come from recently deceased person. Up to now, when a person needs a liver transplant, for whatever reason, it has generally been possible to find a liver. But if the oxycodone/acetaminophen plus alcohol addiction phenomenon continues to increase, there may be a shortage of livers for transplantation.
Irritable bowel syndrome (IBS)
Let’s shift our attention to irritable bowel syndrome (IBS). According to the American College of Gastroenterology, IBS affects about 10% to 15% of adults in the US, or somewhere between 25 and 45 million persons. However, only 5% to 7% of adults have actually been diagnosed with the disease. Almost twice as many women as men are affected by this disease, which is defined by the symptoms, which include cramping, belly pain, bloating, gas, and diarrhea or constipation, or both. Only a small number of people with IBS have severe symptoms. Some people can control their symptoms by managing diet, lifestyle and stress. More-severe symptoms can be treated with medicine and counseling. IBS doesn’t cause changes in bowel tissue or increase risk of colorectal cancer.
Other than the symptoms, the definitions of this disease/malady are imprecise.
The prevalence of IBS varies widely between different countries. The best data available comes from an organization called the Rome Foundation, which is (according to their website) an independent not-for-profit organization dedicated to supporting the creation of scientific data and educational information to assist in diagnosing and treating Disorders of Gut-Brain Interaction (DGBIs), formerly called Functional Gastrointestinal Disorders (FGIDs).
In 2017, the Rome Foundation working group reviewed studies related to IBS which showed that the prevalence of IBS varied from 1.1% in France and also Iran, to 35.5% in Mexico. The prevalence in Asia also varies all over the map. It’s very likely that the studies reviewed by the Rome Foundation did not use uniform diagnostic criteria or the same methodology. Geography, culture, and population characteristics are likely to be reasons for widely different prevalences. The goal of determining the global prevalence of IBS is clearly beyond reach at this time.Even though the mortality figures due to IBS are quite small, it seems unlikely that this syndrome would be a cause of death, unless it morphed into a disease that severely damaged the GI tract, for example peptic ulcers or ulcerative colitis.
The exact cause of IBS isn’t known. Factors that are thought to be possible causes of IBS include:
Muscle contractions in the intestine. The walls of the intestines are lined with layers of muscle that contract as they push food through the digestive tract. Contractions that are stronger and last longer than usual can cause gas, bloating and diarrhea. In contrast, weak contractions can slow food passage and lead to hard, dry stools.
Nervous system. Issues with the nerves in the digestive system may cause discomfort when the abdomen stretches from gas or stool. Poorly coordinated signals between the brain and the intestines can cause the body to overreact to any changes that occur in the digestive process. This can result in pain, diarrhea or constipation.
Severe infection. IBS can develop after a severe bout of diarrhea caused by bacteria or viruses. This is called gastroenteritis. IBS also might be associated with a surplus of bacteria in the intestines, known as bacterial overgrowth.
Early-life stress. People exposed to stressful events, especially in childhood, tend to have more symptoms of IBS.
Changes in gut microbes. Examples include changes in bacteria, fungi and viruses, which typically live in the intestines and play a key role in health. Research indicates that the microbial population in persons with IBS might differ from those in those who don’t have this condition.
It would seem abundantly clear that IBS, along with many other maladies and diseases of the digestive tract, is related to whatever foods that we stuff into our digestive systems. However, according to the Mayo Clinic, the role of food allergy or intolerance in IBS isn’t fully understood. A true food allergy rarely causes IBS. But many people have worse IBS symptoms when they eat or drink certain foods or beverages. These include wheat, dairy products, citrus fruits in particular, but also other fruits, beans, cabbage, and carbonated drinks.
Digestive disease scientists have coined a term for the class of comestibles that can lead to significant digestive distress. The term is FODMAP, which stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols. These are forms of carbohydrates that are found in many of the foods we eat. The common quality of these substances is that our small intestine absorbs them poorly. Some individuals experience considerable digestive distress after eating foods in the FODMAP group. The specific symptoms can include:
Cramping
Diarrhea
Constipation
Stomach bloating
Gas and flatulence
The Low-FODMAP diet works in two phases. First, most foods containing FODMAP are eliminated for a period of two to four weeks. These are replaced with low-FODMAP alternatives. Symptoms are closely monitored for changes. Then specific FODMAPs are reintroduced over a six- to eight-week period, according to patient tolerance. Doctors or nutritionists may suggest keeping a food diary and symptom chart to help identify problem foods as well as track amounts. The goal is to find which foods trigger an individual’s IBS symptoms so these foods can limited or eliminated from, the diet.
Doctors often prescribe over-the-counter medications to treat IBS symptoms. Supplements that contain soluble fiber and osmotic laxatives often reduce IBS symptoms. Many types of prescription medications are used to treat IBS, including anti-inflammatories, immunomodulators, biologics, corticosteroids, and so-called small molecules.
Crohn’s disease
Let’s take a look at another disease of the digestive system. Crohn’s disease is a type of inflammatory bowel disease that causes swelling and irritation of the tissues in the digestive tract, which is can lead to stomach pain, severe diarrhea, and fatigue. It’s hard to pin down a precise cause of Crohn’s disease other than that it is related to general autoimmune inflammation. Patients with Crohn’s disease understandably lose their appetite, and, as a result, can experience weight loss and malnutrition.
Inflammation caused by Crohn’s disease can affect different areas of the digestive tract in different people. Crohn’s most commonly affects the end of the small intestine and the beginning of the large intestine. The inflammation often spreads into the deeper layers of the bowel.
Crohn’s disease can be both painful and debilitating. In some cases, it may lead to serious or life-threatening complications. As noted above, as of 2010. Crohn’s was the reason for 1.1 million visits with health-care providers and was the cause of 611 deaths.
There’s no known cure for Crohn’s disease, but therapies can greatly reduce its symptoms and even bring about long-term remission and healing of inflammation. With treatment, many people with Crohn’s disease can function well and lead relatively normal lives.
Drug treatment for Crohn’s disease runs the gamut from usual over-the-counter drugs for mild symptoms to surgery for severe cases. Drug treatment can consist of any of the following:
Acetaminophen for mild pain.
Antibiotics to prevent or treat complications that involve infection, such as abscesses and fistulas.
Loperamide to help slow or stop severe diarrhea. In most cases, Crohn’s patients take this medicine only for short periods and not when inflammation in the intestines is high, because it may increase the chance of developing megacolon, which is an acute dilation of the colon. In some cases, a result of megacolon is that peristalsis stops and bowel movements cease.
Drugs to treat inflammation in the joints, eyes, or skin.
Calcium and vitamin D supplements or drugs to prevent or slow bone loss and osteoporosis.
In addition to managing inflammation, some drugs may help relieve symptoms. Depending on the severity, one or more of the following may be recommended:
Anti-diarrheals. A fiber supplement such as psyllium (Metamucil) or methylcellulose (Citrucel) can help relieve mild to moderate diarrhea by adding bulk to the stool. For more-severe diarrhea, loperamide (Imodium A-D) may be effective. These medicines and supplements could be harmful or not effective in some people with strictures or certain infections. Patients should consult their healthcare providers before starting these treatments.
Pain relievers. For mild pain, acetaminophen (Tylenol, others) may be recommended. However, nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen (Advil, Motrin), naproxen (Aleve) and diclofenac may make symptoms worse and can make the disease worse as well.
Vitamins and supplements. For patients not absorbing enough nutrients, vitamins and nutritional supplements may be recommended.
Even after drug treatment, many persons will need surgery to treat their Crohn’s disease. Between 30% and 55% of individuals with Crohn’s disease will require surgery within 10 years after diagnosis. Surgery will not entirely cure Crohn’s disease; however, it can treat complications and improve symptoms. Surgery is most often recommended for the treatment of fistulas, abscesses, colorectal cancer, dysplasia, precancerous cells that increase the risk for developing colorectal cancer, life-threatening bleeding, intestinal obstructions caused by scarring, and inflammation and symptoms that don’t improve or stop after treatment with medicines.
Surgery may be recommended if drugs do not improve symptoms. Surgical options include:
A small bowel resection may be necessary in cases of an intestinal obstruction or severe Crohn’s disease in the small intestine.
A large bowel resection may be needed in cases of intestinal obstruction, a fistula, or severe Crohn’s disease in the large intestine.
Another option which is sometimes necessary is an ileostomy, in which surgeons bring the end part of the small intestine—through the abdominal wall and create a stoma, which is a surgical connection between an internal organ and the skin on the outside of the body. After an ileostomy, waste will pass through the stoma. Patients wear a removable pouch, called an ostomy pouch, which is attached to the skin around the stoma to collect the waste.
Sometimes even more radical surgical options may be necessary, such as a proctocolectomy, which is surgery to remove the entire colon and rectum. This will also require a stoma and an external pouch to collect waste.
Patients who have this type of surgery will continue to have the stoma for the rest of their lives.
The causes of Crohn’s disease are shrouded in mystery. More than 200 genes have been associated with Crohn’s disease. However, researchers aren’t exactly sure what role they play in the condition. Having one or more of these genes may make someone more likely to get Crohn’s disease, but having the genes is by no means determinative.
It’s also possible that bacteria, viruses or environmental factors may trigger Crohn’s disease. For example, certain bacteria in our gut are suspected to be associated with Crohn’s disease, but it is not known if these bacteria actually cause Crohn’s disease. When the immune system tries to fight off an invading pathogen or environmental triggers, an atypical immune response can also cause the immune system to attack our own cells in the digestive tract.
The risk factors for Crohn’s disease are somewhat unsurprising. Cigarette smoking is a major risk factor, not only for developing the disease, but for the risk of serious disease and the need of surgery. Family history is a significant risk factor – about 1 in 5 persons with Crohn’s disease have a family member with the disease. White populations have a higher risk of Crohn’s disease, especially persons of Ashkenazi descent. Most people who get Crohn’s disease develop the symptoms before age 30.
Looking over the range of digestive diseases, I don’t find it possible to pick out a common cause. These maladies and disease vary considerably as to symptoms, and the causes are by no means unique to diseases of the digestive tract. Genetic factors can pose risks in just about every disease. But, obviously, the food we insert into our digestive systems is a major possible factor. It can be the carrier of pathogens, or it can be spoiled in some way, or it can carry nutrients that are, in excessive quantities, unhealthy. Of course, harmful germs can get into our digestive systems other ways than in our food. We breathe air, the pathogens lodge in our mucous membranes, and we swallow it. But the single purpose of our digestive system is to do whatever is necessary to convert the stuff that we cram into the entrance to that system into the nourishment that we need to live, and that enormous vital task can encounter glitches, frequently caused by those pathogens. And, of course, any system that is working around the clock to keep us alive is bound to have faults. It’s up to us (and our healthcare providers) to do our best to keep this system working as well as possible.
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As I’ve been working on this piece, my in-box has filled with hopeful news releases, on such topics as Alzheimer’s, Parkinson’s, dementia, and cancer. I’ll compose a dispatch to keep you current on what’s going on.
I appreciate all the comments, so keep’em coming! Best to all, Michael Jorrin (aka Doc Gumshoe)
[ed note: Michael Jorrin, who I dubbed “Doc Gumshoe” many years ago, is a longtime medical writer (not a doctor) and shares his commentary with Gumshoe readers once or twice a month. He does not generally write about the investment prospects of topics he covers, but has agreed to our trading restrictions. Past Doc Gumshoe columns are available here.]
