The gastrointestinal tract begins at the mouth and ends at the anus. In health, the time taken from ingestion to elimination in the Western world is about 1–3 days (Tortora and Derrickson, 2014). This transit time is longer for people with constipation and shorter for people with diarrhoea.
Anatomy and physiology of the GI tract
Mouth and stomach
The mouth contains teeth, required for chewing food, and saliva, which keeps the mouth moisturised and supple as well as being responsible for the first part of the chemical breakdown of food. Once food has been ingested and chewed, it passes to the stomach where chemical breakdown continues with the gastric juices. The stomach is acidic; this helps to prevent infection caused by any ingested bacteria. The stomach's strong muscle walls mechanically churn the food to help to break it down into the various components that are required by the body, such as amino acids, which are broken-down proteins. Food stays in the stomach for several hours while breakdown occurs. Little is absorbed directly from the stomach (Watson, 2011).
Small bowel
When the chyme from the stomach passes into the small bowel, it travels to the duodenum. In the duodenum, the contents are made less acidic by the secretion of pancreatic enzymes and bile released from the gallbladder. The bile, which is produced by the liver, also helps to break down fats.
As the chyme passes from the duodenum into the jejunum and ileum, it is moved along by muscle contractions of the small bowel termed peristalsis. Most nutrients, such as amino acids, are absorbed in the small bowel. Additionally, several litres of fluids from ingestion and secretions are also absorbed. Specific areas of the small bowel absorb different nutrients; for example, the terminal ileum is responsible for absorbing vitamin B12 (Watson, 2011).
Colon
As waste from the small bowel passes into the colon, about a litre of fluid is absorbed and the faeces become more formed. Also in the colon, sodium is absorbed and the bacteria there produce vitamin K and flatus (Waugh and Grant, 2006).
Passage through the colon is slower than through the small bowel, with mass movements that are triggered by eating, for example. When the faeces reach the end of the colon, they enter the rectum where, in health, more faeces are added until the rectal wall distends and triggers the sensation to defecate. If convenient, the anal sphincters will relax and the faeces are eliminated into the toilet.
Diseased GI tract
Many parts of the GI tract can be problematic in disease. An ulcerated mouth can make ingestion painful and this may result in anorexia or weight loss. A diseased small bowel might result in a reduced absorption capacity, which might lead to deficiencies in vitamins, such as vitamin B12 or water-soluble vitamins. If absorption within the intestines is poor, there will be a shorter transit time and the faeces will be looser and more acidic.
A faster transit time also means that stool volume will be increased, resulting in an increased number of defecations each day. Increased frequency of defecation as well as a more acidic faecal output can result in painful perianal skin.
Another problem associated with loose and liquid stool is the greater risk of faecal incontinence, which can reduce quality of life (National Institute for Health and Care Excellence (NICE), 2014). Rectal bleeding may result from ulceration within the gut.
Inflammatory bowel disease
Inflammatory bowel disease (IBD) is a chronic relapsing and remitting autoimmune disease, causing inflammation of the gastrointestinal tract. IBD is a term that incorporates both ulcerative colitis (UC) and Crohn's disease.
IBD affects approximately 400 000 people in UK—about 1 in every 240 people—and arises in men and women equally. Every 30 minutes, someone in UK is diagnosed with IBD (Crohn's and Colitis UK, 2019). This article focuses on people with UC.
Ulcerative colitis
UC is a long-term condition affecting only the colon. Part or all the inner mucosal lining of the rectum and colon becomes inflamed and ulcerated (Mowat et al, 2011). The condition is characterised by superficial and diffuse mucosal inflammation beginning in the rectum and extending in continuity proximally (Kemp et al, 2018). Patients with UC often experience periods of disease relapse and remission.
According to the Montreal classification, three main areas of the colon are affected by UC (Whayman et al, 2011) (Box 1). At diagnosis, in approximately one in three UC patients, disease is limited to the rectum. In another third, the disease extends to the splenic flexure. The remaining third will have pancolitis (Seibold et al, 2014; Ananthakrishnan et al, 2017).
| E1 | Ulcerative proctitis (inflammation involving only the rectum) |
| E2 | Left-sided ulcerative colitis (distal to splenic flexure) |
| E3 | Extensive or pancolitis (proximal to splenic flexure) |
Symptoms of UC
Symptoms of a UC disease flare can include rectal bleeding, bloody and mucous diarrhoea, urgency, tenesmus and a sense of incomplete evacuation; left-sided colicky abdominal pain preceding bowel movements is common.
Severe cases may present with diarrhoea, overt bleeding, fever, tachycardia, anaemia, loss of appetite, weight loss, fatigue, severe abdominal pain, abdominal tenderness and bowel distension with peritoneal signs on examination (Truelove and Witts, 1955; Gisbert and Chaperro, 2018).
For people with disease within the rectum only—proctitis—symptoms are often fresh, rectal bleeding, passage of mucus, urgency and diarrhoea.
Diagnosing UC
The diagnosis of UC is based on a combination of clinical, endoscopic and histological features. It involves taking a medical history, physical examination, clinical evaluation, laboratory investigation and assessing serological markers.
An examination of the colon during colonoscopy reveals erythema and friability of the bowel mucosa with a loss of normal colonic vascular markings. A colonoscopy report will often describe granularity and a contiguous pattern, which signifies loss or change in the mucosal architecture.
Histology frequently shows that the inflammation affects different layers of the bowel, with chronic transmucosal and submucosal inflammation frequently described. Other histological characteristics of UC are crypt abscesses and distortion of the crypt architecture and mucin depletion. Histologic activity may predict risk of disease relapse and subsequent risk of development of colonic neoplasia (Magro et al, 2017).
Medical treatment of proctitis
There are many treatments for IBD. The choice of treatment for UC depends on the degree of activity, course, extent and severity of disease as well as the patient's individual choice (Stange et al, 2008; Cope, 2015; NICE, 2019).
Taking an individualised, therapeutic approach is important. However, before treatment is started, other aetiologies such as infection, toxic reactions to medications and malignancies should be ruled out.
Treatment in this article will focus on topical rectal treatments for people with UC confined to the rectum (proctitis). These treatments are suppositories and enemas.
5-aminosalicylic acid
5-aminosalicylic acid (5-ASA) is an anti-inflammatory drug that reduces inflammation in the intestinal wall and is active only when in direct contact with bowel mucosa. The common name for 5-ASA used with patients is mesalazine (Testa et al, 2017; Kato et al, 2018). 5-ASA is the firstline therapy for mild to moderate UC for induction and maintenance of remission (Ford et al, 2011; NICE, 2020), with well-established efficacy (Harbord et al, 2017). Although other treatments are advocated for more severe UC disease, only treatments for proctitis will be discussed here.
The benefit of topical treatment is that it is applied directly to the inflamed area, such as the rectum, so is more effective than oral medications. Topical medication achieves much higher mucosal concentrations of the drug and works faster and more effectively than oral 5-ASA for people with proctitis (Lamb et al, 2019). Additionally, topical treatment tends to cause fewer side-effects than oral medication as the drug does not enter the bloodstream in significant amounts so does not affect other parts of the body. Topical treatments are suppositories and enemas.
Suppositories
NICE (2019) recommends that treatment for proctitis with mild to moderate activity should be topical treatment in the form of a suppository. 5-ASA suppositories are the firstline medication of choice to induce remission in people with proctitis and are effective in 31–80% of patients (Harbord et al, 2017).
Patients with ulcerative proctitis who do not respond to topical 5-ASA therapies or are intolerant to them can use topical corticosteroid therapy. However, topical corticosteroid therapy is less effective than 5-ASA suppositories in patients with limited distal colitis. Although systemic absorption of steroids with prolonged use is a concern, this appears to be less of a problem with suppositories than enemas or oral medication.
Suppositories are small, waxy, bullet-shaped capsules containing a drug that dissolve at body temperature. The suppository is inserted directly through the anus, releasing the drug as it dissolves within the rectum.
Enemas
5-ASA enemas can be used as an alternative to suppositories, but are not as effective as rectal suppositories for treating proctitis. Enemas travel into the colon, reaching the level of the splenic flexure (Ford et al, 2012). Therefore, enemas are used for patients whose disease also involves the sigmoid colon. 5-ASA enemas are available in foam and liquid form. They are inserted into the rectum through the anus using a specially designed applicator.
Foam enemas can be particularly useful at the beginning of a disease flare. They are often easier to retain and better tolerated than liquid enemas. However, foam enemas do not reach as high in the colon so cannot be used to treat disease in the splenic flexure.
Liquid enemas come in a variety of volumes. Using volumes of more than 50-60 ml can create strong urges to defecate. Liquid enemas are not well tolerated when the patient is experiencing acute disease symptoms; larger volume enemas are better tolerated when used as a maintenance therapy.
Enemas can be used as required up to a maximum of three treatments a day. They can be used in combination with suppositories to enable effective treatment of proctitis and left-sided colitis.
Practical advice on enema insertion
The nurse should advise the patient to insert the enema after emptying their bladder and bowel. The patient should insert the enema in their rectum when standing or lying on their left side. The patient is then advised to lie on their left side for at least 30 minutes to ensure adequate coating of the medication in the inflamed areas.
Patients who have significant bowel urgency may have problems tolerating an enema. In this scenario, the nurse can advise the patient to take the enema at bedtime, so the drug can be absorbed more effectively.
Medication adherence
Cutler et al (2018) state that approximately half of adults and 8% of children worldwide have long-term conditions, which include ulcerative colitis. Poor adherence to treatment can prevent control of chronic disease. Non-adherence is defined as the extent to which the patient does not follow the instruction of a prescriber (Cutler et al, 2018). The reasons for non-adherence are multiple and may be intentional or unintentional.
Medication is a cost-effective way of treating patients with proctitis; however, non-adherence to medication is common. In IBD, non-compliance has been reported as ranging between 7% and 72% of patients (Vangeli et al, 2015). Unfortunately, topical treatment for UC and proctitis has high levels of non-adherence (68%), which can negatively affect patient health outcomes, increase relapse rates, lower patients' quality of life and eventually increase healthcare costs (Dignass et al, 2012). Poor disease control in some cases may lead to hospital admissions (Mongkhon et al, 2018). Therefore, it is important for nurses to encourage patients with proctitis to adhere to their topical treatment regimen.
Improving compliance
There are a number of potential risk factors associated with non-adherence to treatment (Párraga-Martínez et al, 2015) (Box 2).
Fissell et al (2016) report that high pill burden decreases compliance, including with topical medication. This is because of the number of tablets or the need to take medication multiple times each day. Nurses can assess if pill burden is causing a problem with medication compliance and can suggest a once-daily regimen instead. This may be more convenient for patients and improve compliance with medication.
Another potential factor affecting compliance is prescription cost. In the UK, patients with IBD are not exempt from prescription charges and, anecdotally, GPs may release monthly prescriptions only. As patients may be taking two or three medications to keep their IBD in remission, prescription costs can add up and, in some cases, may prove unaffordable, thus resulting in noncompliance (Cutler et al, 2018). Nurses can suggest patients obtain prescription prepayment certificates to reduce costs.
A study by Vavricka et al (2012) reported that convenience, ease of use, time and place of administration were important to patients. It is important for nurses to remind patients not to get discouraged if it takes a few practices before they are able to retain the rectal treatment. Administering the medication at bedtime is practical for most patients, allowing the suppository to be retained for the longest possible time.
Symptom control has also been reported as a significant factor in compliance (Hodgkins et al, 2012). Therefore, the nurse needs to educate patients and remind them to read the patient information leaflet that comes with their medication for instructions on how to administer the treatment in the correct manner. If the patient needs more information, it can be useful for them to talk to their doctor or IBD nursing team. Better compliance with taking the medication as prescribed will help to resolve symptoms.
Adolescent patients are less likely to adhere to medication regimens than older patients, often because of their developmental age. They are trying to deal with their IBD diagnosis, and learning to cope with changes in their body, body image and bowel symptoms. Adolescents are at the age when they are developing their personalities and comparison with their peers is common. Taking medication often singles them out and can negatively affect their psychological development (Plevinsky et al, 2016).
Therefore it is important for nurses to counsel adolescents effectively from the first time they are seen until their transition to an adult clinic. The importance of medication needs to be discussed, including oral and topical drugs, compliance with treatment, the benefits of taking medication regularly, and explaining the risks and outcomes of not taking or missing doses of their medications. Reinforcing their knowledge and the rationale for the route of treatment and how it will alleviate their bowel symptoms is also important. Body image is crucial. Young patients are often not keen to use a rectal preparation. It is important to work with them to find a way that they are happy to take their medication and which preparation is most appropriate for them. More frequent outpatient reviews or telephone consultations are often needed to reinforce disease understanding and that treatments are beneficial.
Patients with mental health issues, anxiety and depression are also at risk of non-adherence to medication regimens. These patients may need extra support to achieve compliance as it has been reported that they are unlikely to engage with and adhere to treatment (Janmohamed and Steinhart, 2017). Support can include the strategies mentioned above and might include more clinic appointments. Nurses need to encourage compliance regularly.
Patients may not feel clear about aspects of their IBD care. Nurses can provide education, counselling and advice, which can include the use of pictures and practical demonstrations. Kamp and Brittain (2018) state that patients who are counselled and well informed about their condition are more likely to comply with treatment. Therefore, a better understanding of their condition, awareness of the outcomes of treatment and its benefits, as well as the impact of non-treatment is crucial in achieving medication compliance and better outcomes.
Patients are often reluctant to start medication because they are concerned about side-effects. Providing information and discussion about treatment options, including potential side-effects, is an important aspect of informed decision making about their treatment (Siegel et al, 2016).
Patients may feel embarrassed or reluctant to administer drugs rectally so introducing them to topical treatments needs to be done with sensitivity. Explaining the benefits of topical treatment and setting realistic expectations of response are vital as patients often cease treatment if symptoms do not resolve immediately. This is important as Seibold et al (2014) highlight that suppositories and enemas are more effective than systemic treatment for proctitis and left-sided disease.
People frequently report forgetting to take medication. Getting into a routine of remembering to take medication every day can be challenging. This is particularly true when patients are taking drugs to stay in remission and have no symptoms. When symptoms improve, the likelihood of missing a medication dose and/or discontinuing treatment is increased. Therefore, advising patients to continue topical treatment regularly even when symptoms resolve is necessary to control subclinical inflammation and prevent recurrence.
Patient expectations of rectal medication may also affect how well they take their medication. They may have unrealistic expectations of how fast improvements will be. To help achieve good adherence to topical medication, patients should be educated on how it works, and on the importance of taking it regularly and in the correct dosage. It is important to encourage patients to participate actively in their care and to communicate any concerns with their IBD team. Additionally, as there is no cure for IBD, it is important to prevent disease recurrence through maintenance therapy even when patients feel well, as this reduces the chance of a disease flare.
Effective maintenance therapy also can mean patients are less likely to require additional drugs. This is because if treatment is stopped and a patient experiences a disease flare, there is a chance that restarting the medication may not work as well, as quickly or even at all. In these cases, other drugs or even surgery may be necessary to control the inflammation.
Consideration should also be given to patient wishes and beliefs, which may be different from the values and opinions of their prescriber. This can potentially hinder decision-making and inadvertently discourage compliance (Kamp and Brittain, 2018). If a drug formulation is not aesthetically acceptable to the patient, allowing the patient to choose the medication modality may improve adherence to treatment.
A number of ways to improve patient compliance with taking their medication are listed in Box 3.
Advice can be reinforced by IBD specialist nurses who work on the ward or in the community. This can be provided when patients are newly diagnosed, in the clinic, during telephone consultations, through advice lines and emails, and when patients are in hospital, for example during ward rounds and drug rounds, as well as on discharge. Support can include reinforcing information verbally, providing written information about drug compliance, educating patients about repeat prescriptions and telling them how to contact the IBD team for advice. It is important to respect the opinion of the patient, once they fully understand the risks and benefits associated with their disease and medications and are able to make an informed decision.
Conclusion
The gastrointestinal tract has several functions and, if various parts of this system do not work correctly, there can be consequences such as diarrhoea, faecal incontinence and a reduced quality of life.
When diseases such as ulcerative colitis occur, specifically proctitis, effective treatment is necessary. To treat proctitis, it is best to target the rectal mucosa directly, using topical rectal medications. If there is disease in the rectum, it is likely that inserting medications will initially be uncomfortable. Therefore, it is important to reinforce the rationale for this route of medication by explaining to patients that there are fewer side-effects and a faster resolution of symptoms if they can use rectal preparations of the drugs.
A positive attitude and belief that treatment is effective is also important. To achieve optimal therapeutic outcomes and ensure medication adherence, it is essential to educate our patients by providing an explanation for the need for medication compliance, so they are able to adhere to the optimal treatment plan.