The Complete Guide to Digestive Health

Tending to your digestive health is critical when striving to live a healthy life. Read how to give your digestive system everything it needs to function properly.

Updated: Thursday 03 November 2022

digestive health guide

Spanning up to 30 feet long, the digestive system is an intricate and vitally important involvement of numerous organs, tasked with the breakdown of food and absorption of useful nutrients. Problems with the digestive system are common, with approximately 4 in 10 people having at least one digestive symptom at any one time [1]. Digestive complications can cause issues absorbing an adequate amount of nutrients, as well as causing abdominal pain and discomfort among a whole host of unfavourable symptoms.

This health centre article aims to cover the common conditions associated with the digestive system, enabling you to prevent and treat abnormalities so you can maximise the efficiency of this essential bodily function.

What’s the Digestive System?

The digestive system is a term used to describe the group of organs involved in digestion (the process of breaking down food, absorbing its nutrients, and removing waste). This includes the gastrointestinal tract (GI tract), which consists of a series of hollow organs joining the mouth to the anus, as well as the solid organs including the liver, pancreas and gallbladder. The oesophagus, stomach, small intestine, large intestine and anus are all vital components in the task of food processing, whereby nutrients need to be broken down into small enough pieces to be absorbed and used for energy, growth and repairing cells. Food moves through the GI tract thanks to the process of peristalsis, in which the muscles in the walls of the various organs contract and relax to push food to the next stage of the digestive system, with mechanical and chemical digestion occurring at the various stages. The small intestine is the organ that absorbs the majority of the nutrients we process (with the help of enzymes secreted from the pancreas), and the circulatory system distributes these across the body for immediate use or storage, a process that the liver is involved in among its other functions. The stool is then stripped of water in the large intestine and passed to the rectum, where the faeces exits through the anus [2].

Treating Common Digestive Conditions

For all elements of the digestive system to work cohesively, we rely on a healthy and balanced diet; our sensitivity to certain food types often dictates how effectively our digestive organs can operate. It’s common to experience issues with digestion, resulting in the following conditions we explore below:


Diarrhoea (also spelt diarrhea) is characterised by loose or watery stools, typically experienced several times in a day. Acute diarrhoea is a common condition almost everyone will experience at some point, usually lasting up to 2 days, whilst chronic diarrhoea lasting several weeks could be a symptom of a chronic disease. On average, adults in the UK experience diarrhoea once per year, and children twice per year [3].

The common causes of diarrhoea include:

  • Bacteria or parasites from contaminated water or food
  • Viruses like the flu, rotavirus (commonly causing diarrhoea in children), or norovirus
  • Food intolerances and sensitivities, such as lactose intolerance
  • Issues with the stomach or colon, such as Crohn’s disease or irritable bowel syndrome (IBS)
  • Medications such as antibiotics or those used to treat cancer

Our tips for preventing and treating diarrhoea are as follows:

  • Treat diarrhoea with medication that hardens the stools, and slows down overactive bowels. Imodium capsules are an affordable over-the-counter treatment that improves diarrhoea symptoms within an hour of taking, and are also available as the orodispersible Imodium Instants for those who find swallowing difficult.
  • Prevent dehydration by drinking plenty of water, and replenish lost electrolytes with Dioralyte sachets or sports drinks.
  • Eat starchy, low-fibre foods that are fairly bland, such as potatoes, bananas, rice, soup and toast.
  • Avoid consuming milk, alcohol, caffeine or spicy foods.

Food Sensitivities

Many people have sensitivities, intolerances or even allergies to certain food types. A food sensitivity or intolerance is triggered by the digestive system, and can cause gas, bloating, constipation, diarrhoea, cramping or nausea. You might be able to eat a small amount of the associated food without any issues. A food allergy, on the other hand, is an immune system reaction that can cause anything from throat irritation to, in some cases, a threat to life (anaphylaxis). Those with food allergies, such as a peanut allergy, should steer clear of consuming even small amounts of the associated food.

It is estimated that around 65% of the population have a reduced ability to digest lactose, making it the most common food sensitivity [4]. Our tips for treating and preventing symptoms of lactose intolerance include:

  • Consume products containing low levels of lactose or that are lactose-free. High lactose products to avoid include milk, ice cream, certain cheeses and cream, all of which are available to purchase in lactose-free variants. If you must eat these foods, do so with plenty of other low-lactose food to lessen the symptoms.
  • Dairy foods containing active cultures, such as probiotic yoghurt, are fine to consume; the bacteria in these products help break down their lactose and so will be more easily digested.
  • Take lactase enzyme tablets when you consume dairy products. Those that are lactose intolerant are deficient in the lactase enzyme needed to digest dairy sugars into glucose and galactose, so this supplement tops up the lactase levels, enabling better digestion.

Acid Reflux and GORD

Acid reflux occurs when stomach acid rises into the oesophagus, causing irritation of it’s lining. The stomach lining is adapted to be protected against this powerful acid, however, the oesophagus is not, so when the lower oesophageal sphincter fails to tighten properly, stomach acid can flow in the wrong direction. This can leave a bitter taste in the mouth, as well as causing a burning sensation in the chest known as heartburn. If this is an issue you experience frequently, you may have the chronic form of the condition, known as gastro-oesophageal reflux disease.

To prevent and treat acid reflux and GORD, you should try the following tips:

  • Slow your eating, and don’t lie down too soon after eating.
  • Avoid foods that can trigger acid reflux, such as spicy or high-fat foods, onions, alcohol, coffee, milk and chocolate. Also steer clear of carbonated drinks.
  • Try to be more active, as low levels of exercise and benign overweight are common risk factors.
  • Take over-the-counter medications such as Gaviscon Tablets, Gaviscon Liquid and Gaviscon Sachets to neutralise stomach acid and relieve discomfort.
  • If eligible, take prescription acid reflux treatments such as Omeprazole, Lansoprazole and Pantoprazole. These medications are known as proton pump inhibitors, and are regarded as more effective long term solutions to OTC treatments.

Irritable Bowel Syndrome (IBS)

Approximately 11% of the worldwide population suffer from IBS, a condition that causes stomach cramps, bloating and gas, as well as stools that fluctuate from dry and hard to loose and watery [5]. The exact causes of IBS are not known; it has been linked to the way in which food passes through the gut, an oversensitivity of the nerves in the gut, stress, and family history of IBS. Whilst there is no cure, dietary changes and medicines typically help manage the symptoms.

To treat IBS, try the following tips:

  • To identify if certain foods trigger your IBS, keep a food diary of what you eat each day, so you can trace back your symptoms to particular food types. Once established, avoid consuming these foods. Foods that typically trigger IBS symptoms include dairy products, alcohol, caffeine, artificial sweeteners and foods that produce gas such as legumes. Consuming more low-fat, high-fibre meals is recommended. Following a low FODMAP diet has shown to reduce IBS symptoms.
  • Take probiotic supplements. Certain probiotics, such as Saccharomyces boulardii, bolster your gut microbiome, and support the digestive system. Be aware that not all probiotics are alike, so be sure to double check which supplements are most suitable for IBS in particular.
  • Take over-the-counter IBS treatments, such as Buscopan tablets or Senocalm tablets, to alleviate symptoms like abdominal cramps or gastrointestinal spasms.


Constipation is characterised by bowel movements that are both infrequent and difficult to pass. This can lead to additional straining and time spent on the toilet. Whilst periodic constipation is likely due to factors such as dehydration or not enough fibre in the diet, more serious cases can be caused by high stress, spinal injuries, hormonal changes, muscle issues or cancers.

The following tips will help to relieve symptoms of constipation:

  • Ensure you have enough fibre in your diet. Foods that are high in fibre include oats, whole-grain bread or cereals, rice and beans, and fibrous fruits and vegetables.
  • Drink plenty of water, as this is essential for normal bowel movements.
  • Try gentle exercise, such as a daily walk or run.
  • If still experiencing constipation, you may wish to consider a laxative. First, you should try taking a Fybogel which is a bulk-forming laxative, to relieve constipation in a gentle way. If this is not enough, you may instead try an osmotic laxative such as Laxido sachets or Movicol sachets. These soften the stool, whilst replenishing the electrolytes help to maintain the body’s normal sodium, potassium and water levels.
  • If the stools are soft but still difficult to pass, you may wish to take stimulant laxative medication. Bisacodyl, Dulcolax and Dioctyl stimulate the enteric nerves in the GI tract, causing contractions in the colon that help move stools. They also act as contact laxatives, increasing the fluid and salt that passes through stools, softening them. Senna and Senokot are natural, plant-based tablets that work by irritating the colonic wall to stimulate the bowel. It is important that stimulant laxatives are only used for short-term relief of occasional constipation. Long-term use may be harmful, therefore you should see your GP if you still have symptoms after one week.


Also known as Pinworm, these are parasitic worms that cause itchiness of the anus and waking up in the night. Whilst most commonly found in children, threadworms' contagious nature means they can spread to the entire family if not treated. They lay eggs near the anus, and when itched, the eggs can get caught under the fingernails, making them easy to pass on when things are then touched.

To prevent and treat threadworm, follow the tips below:

  • Take treatment for threadworm. This oral tablet treatment prevents the threadworms from using glucose in the body, which they require to survive, clearing the infection within a few days.
  • Regularly wash your hand, scrubbing under the fingernails with a soft brush.
  • Keep your fingernails short and try not to bite your nails.
  • Wear tight underwear and change your sleepwear regularly.
  • Wash underwear and bed linen in hot water.

Hemorrhoids (Piles)

This common condition affects approximately 75% of adults over the age of 45 [6]. Piles occurs when the blood vessels at the end of the digestive tract become inflamed, causing itchiness, pain or even bleeding around the anus. Piles can be caused by chronic constipation, diarrhoea, excessive straining during bowel movements, and a lack of fibre in the diet.

The below tips will help to reduce the severity of piles symptoms:

  • Eat foods that are high in fibre or take a fibre supplement such as Fybogel sachets.
  • Topical ointments such as Anusol Cream can be used to relieve symptoms of piles, such as itching and swelling. Rectal suppositories such as Anusol Suppositories can also treat piles, with the benefit of rapid absorption and providing medication directly where it’s needed.
  • Warm baths can help soothe the irritation from piles, especially immediately after bowel movements. The addition of epsom salts can provide greater relief and reduce the pain.
  • For more serious haemorrhoid bumps that cause pain and regular bleeding, a hospital treatment might be required to remove them. This can include non-surgical procedures such as rubber band ligation, electrotherapy, or infrared coagulation, or haemorrhoidectomy for more severe cases.

The NHS advises that if you receive any of the following symptoms, this could be a warning of a serious digestive illness, and you should see your doctor straight away [7]:

  • A sudden, persistent change in the pattern of how your bowels work
  • Bleeding from the bottom
  • Worsening heartburn, indigestion or stomach pain
  • Losing weight unexpectedly
  • Difficulty swallowing
Amber Mitchell-Hanna

Written by: Amber Mitchell-Hanna

Pharmica Medical Writer

Amber is an experienced writer and content specialist, graduating from De Montfort University with an LLB & an MA in Investigative Journalism.

She particularly enjoys creating informative health content, debunking medical misconceptions, and championing inclusion and diversity.

Find out more about how we ensure the accuracy of our content with our content guidelines.

5 Common Acid Reflux Triggers
5 Common Acid Reflux Triggers