Problems of the lower GI tract

Some of the symptoms of lower gastrointestinal disorders can be vague and overlapping, so careful questioning is required when advising pharmacy customers.


Learning objectives

After reading this feature you should be able to:

  • Understand potential risk factors and triggers for IBS
  • Recognise the hallmark symptoms of IBS
  • Know how to recognise and manage other lower GI disorders.


Irritable bowel syndrome (IBS) is a chronic, relapsing and life-long disorder that affects an estimated 10-20 per cent of the UK population (around 12 million people), yet it remains poorly understood and is often dismissed as trivial.

According to the IBS Network, the UK’s leading charity supporting people with IBS, “this is an illness with no specific cause, no distinctive pathology and no single effective treatment”. Those affected by IBS most commonly fall in the 20-30 year age bracket – although recent trends suggest an increasing proportion of older sufferers. The condition is twice as common in women than men.

Currently, IBS costs the NHS around £200 million per year and ranks as a leading cause of both GP visits and secondary care referrals. In addition to its health economic burden, IBS has a significant negative impact on quality of life and is often accompanied by feelings of depression and anxiety.

Recent data have revealed that a third of patients with IBS were forced to visit their GP at least five times before receiving a diagnosis, with 44 per cent of sufferers reporting that these delays in diagnosis and treatment impacted adversely on their quality of life. Studies have also highlighted the hidden mental stress associated with IBS symptoms centred around issues such as access to bathroom facilities, privacy while toileting, and avoidance/timing of eating.

Recognising risk factors and spotting symptoms

The cause of IBS remains unclear but it is thought to be due to problems associated with digestion and heightened gut sensitivity.

Common risk factors for disease development include an attack of gastroenteritis, a traumatic or psychologically distressing event or a course of antibiotics. According to the IBS Network, these factors “reset the gut to a state of excitation” by stimulating the gut immune response, inducing mild inflammation, depleting colonic bacteria and increasing gut sensitivity.

In keeping with this sensitivity/excitation theory, anxiety and stress are recognised to be key trigger factors that can bring on a bout of IBS. Almost three-quarters of sufferers report that anxiety and stress exacerbates their gut symptoms.

The hallmark symptoms of IBS include abdominal cramps (often relieved by going to the toilet), bloating, diarrhoea, constipation and frustrated defaecation. Customers may also experience other nebulous and non-specific symptoms such as tiredness, nausea, heartburn and indigestion, backache, frequent urination, headaches, muscle pains, anxiety and depression. 

Broadly speaking, pharmacists should consider potential IBS in any customer who fits the overarching ABC criteria for at least six months:

  • Abdominal pain or discomfort
  • Bloating
  • Change in bowel habit.

Confirming a diagnosis

The presentation of IBS often overlaps with other GI conditions, such as non-ulcer dyspepsia or coeliac disease, so establishing a firm diagnosis is key, and may require sensitive questioning to expose the full range of signs and symptoms.

According to NICE, a definitive diagnosis of IBS requires the presence of abdominal pain or discomfort that is relieved by defaecation or associated with altered bowel frequency or form and at least two of the following four symptoms:

  • Altered stool passage (straining, urgency, incomplete evacuation)
  • Abdominal bloating (commoner in women than men), distension, tension or hardness
  • Symptoms made worse by eating
  • Passage of mucus.

Other features, such as lethargy, nausea, backache and bladder symptoms, are common in people with IBS and may be used to support the diagnosis.

In general, people with IBS present with one of three characteristic symptom profiles, most commonly:

  • Diarrhoea predominant
  • Constipation predominant
  • Alternating profiles.

For any patient with IBS, it is vital to rule out signs and symptoms that may point to potential cancer or an underlying inflammatory bowel disease. These red flags include:

  • Unexplained weight loss
  • Swelling or lumps in the abdomen or rectum
  • Rectal bleeding
  • Signs suggestive of anaemia
  • A family history of bowel or ovarian cancer.


Tackling IBS requires a multipronged approach incorporating general lifestyle interventions together with symptom-targeted medications. Unsurprisingly, diet and nutritional change is central to the management of IBS and key advice to sufferers should include:

  • Consuming regular meals and taking time over eating
  • Avoiding skipping meals or leaving long gaps between eating
  • Drinking at least eight cups of fluid each day, particularly water and other non-caffeinated beverages
  • Limiting tea and coffee consumption to a maximum of three cups daily
  • Reducing intake of alcohol and carbonated drinks
  • Limiting intake of ‘resistant starch’ (i.e. starch that resists digestion in the small intestine and reaches the colon intact). This is often found in processed or re-cooked foods
  • Restricting fresh fruit intake to three 80g portions per day
  • Avoiding the artificial sweetener, sorbitol, which is found in sugar-free sweets (including chewing gum) and drinks, and in some diabetic and slimming products.

Although advice on an IBS-friendly diet is important for any sufferer, customers should be made aware that there is no ‘one size fits all’ dietary solution for solving IBS. Determining the optimal approach requires personalised monitoring and tracking symptoms and reactions to different foods, usually using a food diary.

If a customer can identify the specific foods, or food groups, that make their symptoms better or worse, they can then tailor their diet accordingly and, in particular, avoid known triggers of the condition.


Fibre can be a confusing issue for IBS sufferers


Fibre can be a confusing issue in IBS and unravelling it requires understanding the difference between soluble forms (found in oats, barley, rye, fruit, root vegetables and golden linseeds) and insoluble fibre (contained in wholegrain bread, bran, cereal, nuts and seeds). People with diarrhoea symptoms of IBS may benefit from reducing their intake of insoluble fibre, as well as avoiding eating the skin, pith and pips from fruit and vegetables.

Conversely, constipation-predominant IBS sufferers should increase their consumption of soluble fibre by eating highfibre foods or supplementing with ispaghula powder. NICE also suggests that people with wind and bloating may find it helpful to eat oats (e.g. an oat-based breakfast cereal or porridge) and linseeds (up to one tablespoon per day).

Low FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols) diets are a relatively new nutritional treatment approach in the IBS arena. The IBS Network explains that FODMAPs are “a collection of poorly absorbed simple and complex sugars that are found in a variety of fruits and vegetables and also in milk and wheat.

After digestion of a meal, they pass through the stomach and small intestine unchanged and are either fermented by colonic bacteria releasing gas or expelled together with fluid. In people with a sensitive gut of IBS, they can cause symptoms of bloating, abdominal pain and diarrhoea”.

Adopting a low FODMAPs diet essentially involves restricting intake of foods high in FODMAPs, such as some fruits and vegetables, animal milk, wheat products and pulses. Detailed information on FODMAPs and their role in IBS can be found at: kcl.ac.uk/lsm/research/divisions/dns/projects/fodmaps/faq.aspx.

Other key self-care advice for customers with IBS should include increasing physical activity, reducing stress levels and promoting relaxation. A minimum of 150 minutes of moderateintensity aerobic activity is recommended per week and may be particularly beneficial for patients with low baseline activity levels. All customers with IBS should also be encouraged to identify and maximise their available leisure time, as well as carving out opportunities for relaxation.

Options to explore include relaxation techniques like meditation or mindfulness, or activities that promote relaxation such as yoga and tai chi. Reducing stress levels is important as this can help to ameliorate both the severity and frequency of IBS symptoms.

The use of aloe vera in the treatment of IBS should be discouraged and there is also very little in the way of robust clinical evidence to support the value of prebiotics. Patients who choose to try these products should be advised to continue treatment for at least four weeks to monitor any potential therapeutic effects and to always follow the manufacturers’ recommendations on dosage.

Pharmacological therapy

Pharmacological therapy for IBS is driven primarily by the nature and severity of the predominant symptoms. Bulk-forming laxatives can be beneficial for patients with IBS that is constipation predominant; however lactulose is not recommended.

Customers taking laxatives should be advised to:

  • Ingest plenty of fluids while on treatment
  • Start at a low dose of medication and gradually increase the dose every few days (if required)
  • Avoid bedtime administration.

Antispasmodic remedies (e.g. hyoscine butylbromide, mebeverine and therapeutic peppermint oil) may prove helpful if a customer’s IBS symptoms include stomach pain and/or cramping. For IBS with diarrhoea, loperamide is the first choice antimotility agent recommended by NICE. Pharmacists should advise customers with IBS to adjust their individual doses of laxative or antimotility agent according to clinical response, with the overall aim of treatment being to achieve a soft, well-formed stool.

As a second-line treatment for IBS where laxatives, loperamide or antispasmodics do not deliver sufficient relief for patients, tricyclic antidepressants or selective serotonin reuptake inhibitors (SSRIs) can be considered. Prescription-only, they work by blocking nerve signal transmission to and from gastrointestinal nerves.

In a further step forward in IBS pharmacotherapy, NICE has recently given the green light to a new medication for patients with IBS with diarrhoea who have failed to respond to, or are unable to take, other treatments. Eluxadoline (Truberzi) is a mu- and delta-opioid receptor antagonist that works by binding to opioid receptors in the digestive system to slow the movement of food through the gut.

In two phase III trials, the drug demonstrated a significant reduction in abdominal pain and diarrhoea, says Allergan, with fast and sustained relief for over six months. 


Key facts

  • Irritable bowel syndrome affects an estimated 12 million people in the UK
  • Diet, nutritional and lifestyle interventions are the cornerstone of IBS management
  • Pharmacological treatment options include antispasmodics, laxatives, antimotility agents and antidepressants



Other lower GI conditions: an overview


Although a key symptom of IBS, diarrhoea also has a myriad of other potential causes – the commonest of which is acute gastroenteritis. Important microbes that cause bowel infection and can trigger diarrhoea include norovirus or rotavirus, food-poisoning bacteria (e.g. Campylobacter and E-coli) or parasites.

Other potential causes of short-term diarrhoea that should be considered include anxiety, excessive alcohol consumption, food allergy and appendicitis. Diarrhoea is also a recognised side-effect of many types of medication including antibiotics, magnesium-containing antacids, NSAIDs, SSRIs, statins and some chemotherapy drugs.

Most cases of diarrhoea are self-limiting, resolving within two to four days (five to seven days in children). OTC antidiarrhoeal medications containing loperamide can be recommended for adults to help ease symptoms. The prescription drug, racecadotril, which decreases intestinal secretion of water and electrolytes but (unlike loperamide) does not slow intestinal transit, is an alternative option for adults and children from three months of age.

For anyone suffering from diarrhoea, advice on dehydration prevention is essential. Adults should be encouraged to drink plenty of fluids, ideally containing water, salt and sugar. Oral rehydration solutions may be recommended for children or frail, elderly adults at high risk of dehydration. Customers should be encouraged to resume (or continue eating) during episodes of diarrhoea, if possible, but to stick to small light meals and avoid excessively fatty or spicy foods.


Constipation is a subjective term that covers symptoms including infrequent stools, difficult stool passage or the inability to completely empty the bowel. Stools are often dry and hard and may be abnormally large or small. Constipation is a common problem across all ages. Factors that increase the likelihood of constipation include low dietary intake of fibre, immobility and lack of exercise, insufficient fluid consumption, being over or underweight and anxiety/depression.

Constipation is particularly common during pregnancy (where around 40 per cent of women are affected) due to increased production of the muscle relaxing hormone progesterone, which reduces normal bowel peristalsis. In the general population, constipation is twice as common in women as men and seen more in the elderly.

Constipation may be caused by medication, with key culprits including opiate painkillers, aluminium-based antacids, antidepressants, antiepileptics, antipsychotics, calcium or iron supplements and diuretics. Diet and lifestyle changes are key to the first-line management of constipation, and advice should include:

  • Increasing fibre intake to 18-30g per day
  • Adding bulking agents such as wheat bran to the diet
  • Drinking plenty of fluids
  • Exercising regularly
  • Keeping to routine toileting habits that respond to the bowel’s natural pattern.

It is also important to adjust the use of any constipating medication where possible. Oral laxatives can be offered if dietary measures prove ineffective or while waiting for these to take effect, starting with a bulk-forming laxative (e.g. ispaghula husk, methylcellulose or sterculia). Adequate fluid intake is essential for this type of laxative, which works by boosting retention of water in the bowel. If stools remain hard, options include adding or switching to an osmotic or stimulant laxative.

In the specific case of opioid-induced constipation, bulk-forming laxatives should be avoided. All customers should be advised to stop taking any laxatives as soon as stools become soft again and easily passed.

Ulcerative colitis

Ulcerative colitis (UC)5 is a type of autoimmune inflammatory bowel disease (IBD) associated with inflammation of the lining of the rectum and parts of the colon. UC is most commonly diagnosed in people aged 15-25 years of age. As the name suggests, tiny ulcers form on the lining of the affected parts of the gut, which may also bleed and produce pus.

Classic features of UC include:

  • Bloody diarrhoea lasting more than six weeks or rectal bleeding
  • Faecal urgency
  • Nocturnal defaecation
  • A persistent, painful urge to defaecate even when the bowel is empty
  • Cramping stomach pain
  • Predefaecation pain.

Other more generalised symptoms also common in patients with UC include tiredness and fatigue, general feelings of unwellness or fever, loss of appetite, and weight loss and anaemia. 

The specific symptoms experienced by an individual with UC depend on the extent and severity of their gut inflammation. The disease is also characterised by periods of remission interspersed with relapses and flare-ups. One-third of UC sufferers will additionally develop disease manifestations outside the digestive system affecting the joints, eyes and skin.

Treatment options for UC include aminosalicylates (ASAs), corticosteroids and immunosuppressants. The dual goals of therapy are to relieve symptoms and flare-ups, and maintain ongoing disease remission.

Crohn's disease

Unlike IBD, which is limited to the bowel, Crohn’s disease can affect any part of the GI tract from the mouth to the anus, but most commonly occurs in the ileum or colon. The areas of inflammation are typically patchy, interspersed with segments of normal gut, and penetrate deep into the bowel wall. The commonest symptom of Crohn’s disease in adults is diarrhoea, which may contain blood or mucus. Other generalised symptoms are similar to UC and include stomach pain, fatigue and unintentional weight loss.

Crohn’s disease typically onsets between 16-30 years of age, but incidence spikes again in the 60-80 year age bracket. For any customer with Crohn’s, advice on smoking cessation is key because smoking is associated with more severe symptoms and may also hamper efforts to maintain remission.

Treatment aims in Crohn’s are similar to UC and therapeutic options include corticosteroids, immunosuppressants and biologicals. Surgery is often required in patients with Crohn’s disease and may include a bowel resection to remove diseased sections of gut or a temporary ileostomy.

Customers should be made aware that there is no 'one size fits all' dietary solution for managing IBS

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