Earlier this week I blogged about the importance of what we introduce into the gut by mouth. The food then enters the digestive system and the important nutrients are digested.
In the mouth the tongue pushes food to the back of the mouth and through the act of swallowing passes into the muscular tube called the oesophagus ( from the Greek meaning entrance to eating and often referred to as the gullet) The oesophagus releases mucus to lubricate food and muscles push the meal downwards by peristalsis into the stomach.
A patient came into this week very concerned that she was having a tube put into her sarcophagus(is a box-like funeral receptacle for a corpse)did that mean things were very serious! She was due to have an endoscopy so I was quick to reassure her that things were not that bad.
The stomach is a j-shaped organ found between the oesophagus and duodenum. Its main function is to help digest the food you eat. The other main function of the stomach is to store food until the gut is ready to receive it. You can eat a meal faster than your intestines can digest it.
Digestion involves breaking food down into its most basic parts. It can then be absorbed through the wall of the gut into the bloodstream and transported around the body. Just chewing food doesn’t release the essential nutrients, so enzymes are needed.
The wall of the stomach has several different layers. The inner layers contain special glands. These glands release enzymes, hormones, acid and other substances. These secretions form gastric juice, the liquid found in the stomach.
Muscle and other tissue form the outer layers. A few minutes after food enters the stomach the muscles within the stomach wall start to contract (tighten). This creates gentle waves in the stomach contents. This helps to mix the food with gastric juice.
Using its muscles, the stomach then pushes small amounts of food (now known as chyme) into the duodenum. The stomach has two sphincters, one at the bottom and one at the top. Sphincters are bands of muscles that form a ring. When they contract the opening, the control closes. This stops chyme going into the duodenum before it is ready.
It is when this process goes wrong that problems occur. Almost everyone knows what it feels like to have indigestion also known as dyspepsia,heartburn or nausea. The Chinese call it reversal of Qi as stomach Qi should descend. This should occur as a ‘one-way’ movement but reflux can occur when food or drink travels back up from the stomach and into the oesophagus. This is not the same as vomiting, which is a violent reaction, reflux can occur without people even realising. At the lower end of the oesophagus, there is a ring of muscle which is there to stop reflux. This generally works efficiently – when we eat or drink, the muscle relaxes but it then tightens up when we have finished. However, if the muscular ring gets too slack, reflux can occur. If reflux occurs repeatedly, it may lead to oesophagitis – inflammation of and damage to the lining of the oesophagus. In most cases, there seem to be no obvious causal factors leading to the slackening of the oesophagus’s muscular ring, although eating an excess of rich, fatty foods does seem to increase reflux. Treatment generally takes the form of medication – although lifestyle modifications can help too.
It is estimated that 40% of people have a digestive symptom at any one time usually describing one of 4 symptoms:-
changes in bowel habit (usually constipation or diarrhoea)
Hence, it’s not surprising that when I sit in an out of hours clinic that so many people present with one of these symptoms.
Most digestive problems are to do with lifestyle, the foods eaten, or stress. Another common cause is the use of non-steroidal anti-inflammatory drugs(NSAIDS) such as ibuprofen, aspirin, naproxen or diclofenac.
Taking steps to change your lifestyle can help, and often prevent, many of these problems. There is a wide choice of pharmacy remedies for heartburn, indigestion and similar problems that are very good for the short-term relief of symptoms but it is interesting that very few of these people have tried anything before they are seen by a doctor.
I remember as a child my father taking either white medicine or sucking white tablets. Then early one morning he was taken by emergency ambulance to hospital and had emergency surgery for a perforated ulcer. He was in hospital for almost 4 weeks and then sent to a convalescence home.
When I was studying medicine and when I qualified this type of patient was not uncommon and I spent many hours holding a retractor assisting surgeons carrying out varied types of surgery, cutting nerves, removing part of the stomach in order to eleviate these symptoms in an emergency or as an elective procedure. Then there was a major breakthrough and drugs such as cimetidine and ranitidine (Zantac) were introduced. These decreased the amount of acid produced and often cured the digestive symptoms. These drugs are now readily available over the counter. However, I remember in the small Welsh town where I worked that the value was such that a doctor and pharmacist were prosecuted for trafficking these drugs to Asia! The doctor was my Registrar so I had instant promotion.
One day in 1982 I was reading Scientific American,a favourite journal for many years, and I was drawn to a very interesting article written by 2 Australian scientists who had been examining gastric mucosa for many years and they had observed a bacterium called Helicobacter pylori was frequently seen (in 80% of specimens)but assumed to be insignificant but they were the first to show that it played a part in the formation of ulcers. Individuals infected with H. pylori have been shown to have a 10 to 20% lifetime risk of developing peptic ulcers and a 1 to 2% risk of acquiring stomach cancer.
The Helicobacter pylori enter the stomach and attach to the protective mucus lining of the stomach wall. The bacteria are able to survive in the strongly acid environment of the stomach because they excrete the enzyme urease which neutralized the acidic environment of the stomach by converting urea into the basic ammonia and buffer bicarbonate. Inside the mucus lining of the stomach wall, the bacteria cannot be killed by the bodies immune system.
The Helicobacter pylori produce toxins such as vaculating cytotoxin A (VAC A) that cause the cells in the lining of the stomach to die. This allows the bacteria to better access of nutrients as it decreases the competition from stomach lining cells.
The bacteria invade the protective inner lining of the stomach so that they can be protected from immune system. The bacteria then kill the cells that they invade which creates holes in the mucus lining of the stomach, causing the formation of ulcers. Additionally, the substances released by the bacteria during the invasion, hurt the stomach cells ability to absorb calories from food in the stomach.
This is the reason why patients with stomach ulcers and cancer can lose significant amounts of weight.
At least half the world’s population are infected by the bacterium, making it the most widespread infection in the world.
It used to be said that in the developed World that the prevalence of infected people increases with age and is the same percentage as age – 50% of 50 year olds were infected but this is now changing.
In 1979 the first of a new class of drug, omeprazole that controls acid secretion in the stomach (proton pump inhibitor-PPI) was discovered.
Once H. pylori is detected in a person with a peptic ulcer, the normal procedure is to eradicate it and allow the ulcer to heal. The standard first-line therapy is a one week “triple therapy” consisting of proton pump inhibitors such as omeprazole and the antibiotics clarithromycin and amoxicillin. Variations of the triple therapy have been developed over the years, such as using a different proton pump inhibitor, as with pantoprazole or rabeprazole, or replacing amoxicillin with metronidazole for people who are allergic to penicillin. Such a therapy has revolutionized the treatment of peptic ulcers and has made a cure to the disease possible; previously, the only option was symptom control using antacids, H2-antagonists or proton pump inhibitors alone.
Now, the modern medical student or junior doctor will have never seen surgery for this condition and the majority patients are treated and cured in the community.
It is important that anyone aged 55 years and older with unexplained and persistent recent-onset dyspepsia alone should also have endoscopy.
Also alarm signs at any age such as
haematemesis,( vomiting blood)
require urgent referral for endoscopy.