Exploring common bowel symptoms

Written by: Mr Parv Sains
Edited by: Carlota Pano

As a vital component of the digestive system, the bowel plays a multifaceted role in processing food, absorbing nutrients, and eliminating waste. Understanding and addressing bowel symptoms is thus crucial for proactively managing our health.


Here, Mr Parv Sains, renowned consultant general surgeon, provides an expert insight into the most common bowel symptoms, unravelling their potential causes and offering insights into their effective diagnosis.



What causes bowel symptoms like diarrhoea or constipation?


Diarrhoea can be caused by anything.


Acute infections (viral infections) are a very common cause. Issues like norovirus and other gastrointestinal viruses or food poisoning can cause diarrhoea, but this is normally very short-lived and resolves on its own.


Causes of chronic diarrhoea are things like inflammatory bowel disease (ulcerative colitis and Crohn’s disease).


More significantly, on the oncological side, bowel cancers can present with a change in bowel habit, which is typically increased bowl frequency. Sometimes, bleeding is involved as well.


Another cause of diarrhoea are polyps, especially large polyps of the bowel, because they can irritate the bowel and cause mucus secretion. Bowel frequency then increases.


Other causes of diarrhoea are things like microscopic or lymphocytic colitis, which is a lesser form of colitis normally treated with a short course of steroids.


In addition, patients who had their gallbladder removed can also get loose stool in the long run.


There are also conditions such as coeliac disease, which can present as diarrhoea and loose stool or food intolerances.


Constipation is mainly due to dietary causes, where patients are eating meals with a reduced fibre content and they’re not drinking enough fluids to soften the stool.


There are certain conditions which can predispose towards constipation, such as high calcium in the blood which can be caused by parathyroid problems. The other thing that can cause constipation is low thyroid function.


Besides this, there are lots of medications that can constipation as well, such as codeine.


In any case, it’s important to go through the patient’s drug history before starting treatment for constipation. The first thing we have to be sure of is if constipation is long-standing. If constipation is very acute and the patient is feeling very uncomfortable and their tummy is distending, then we have to make sure that there isn’t an obstruction or a blockage.


Constipation should be investigated, especially if it’s acute and it involves abdominal distension. The investigations are either with a colonoscopy or a CT scan.


Diarrhoea, a change towards diarrhoea, and increased bowel frequency is slightly more concerning.


When should I see a doctor for bowel issues?


If you have a change in bowel habit which lasts more than 10 days, especially if it’s towards increased toilet frequency and a looser stool, then it’s worth seeing the doctor because it could be a viral or bacterial infection. If you have a change in bowel habit with associated bleeding that has been going on for a couple of days, then I would probably go much sooner.


If you have bowel symptoms which are acute, like abdominal distension or pain and discomfort, then you should go to the emergency department straight away.


A small amount of fresh rectal bleeding is typically normal and caused by haemorrhoids or fissures. However, if rectal bleeding has been going on for more than a couple of weeks, then it’s better to seek advice from the doctor.


How can diet affect bowel health?


A lot of research has been conducted on the microbiome of the gut, and more and more evidence now shows that whatever we eat or whatever our bacterial gut health is like will dictate how our overall health will be. In very simplistic terms, our bowel will function better if we have a moderate intake of fibre. This means eating all the vegetables, fruits, wholemeal breads, and drinking plenty of water.


Diarrhoea, constipation, erratic bowel habits, abdominal discomfort, and bloating are all intricately linked to what we eat. As a result, there was a tendency in the past to recommend a high fibre diet to manage these issues.


Nowadays, the recommendation is to eat a tailored diet suited to your specific needs, where things like food diaries are becoming more important given their ability to cross reference what we eat with what our symptoms are like. With this information, we can then start excluding or including foods that will make us feel better as far as our bowel goes.


Regardless, the microbiome situation is quite an interesting one and I think we’re probably going to see more and more cases where we start adjusting our diets, according to our gut bacterial colonisation, for the benefit of our overall health.


What are the warning signs for serious bowel problems?


The warning sign is usually a change in bowel habit, which typically involves going to the toilet more often with looser stool. If there is bleeding involved, whether it’s fresh blood or dark blood, then it becomes something that really needs to be looked at. In addition, bleeding by itself can also be a sign of a serious issue like a bowel polyp or bowel cancer.


If it gets to the point of abdominal pain, abdominal discomfort, or weight loss, then this is certainly concerning especially if there has been a change in bowel habit. What we’re looking at here, unfortunately, is probably a more advanced stage of bowel problems. For this reason, it’s important that patients contact their doctors early on as regards to investigations.


If you have rectal bleeding and/or a change in bowel habit, especially if you have a family history of bowel polyps, then it’s worth an early investigation.


What tests are used to diagnose bowel issues?


Non-invasive tests, such as blood tests, can be done. The main blood test is a full blood count to rule out anaemia, because anaemia can be a sign of a bowel problem. Sometimes, certain polyps and bowel cancers can sit on the right side of the bowel and the patient becomes anaemic without realising.


In addition, there are also other blood tests, such as the tissue transglutaminase antibody (TTG) test to rule out coeliac disease, as well as thyroid function, calcium, and liver function tests. All these are very important to tie into the bowel.


Then, the specific tests that can be done to look at the bowel are plain X-rays and CT scans. A flexible sigmoidoscopy, which is half a colonoscopy, can also be used in certain circumstances.


The gold standard test to look at the large bowel is a colonoscopy, which is a procedure to look at the entire lining of the bowel from its first part right down to the anus. If there are biopsies that need to be taken, these can be performed during the colonoscopy as well.  



If you require expert diagnosis and treatment for bowel symptoms, schedule an appointment with Mr Parv Sains via his Top Doctors profile today.

By Mr Parv Sains

Mr Parv Sains is a leading general surgeon based in Sussex and London. He has a specialist interest in coloproctologylaparoscopic (keyhole) surgery and hernia surgery. He is an expert in treating hernias and haemorrhoids and other perianal conditions such as fissures and fistulas. He also performs bowel surgery and gallbladder surgery for gallstones.

Mr Sains qualified from the University of Birmingham Medical School before undergoing surgical training in London in the South-West Thames training region. He undertook a two-year fellowship at St Mary's Hospital, Imperial College London. During this time, he was also an honorary research fellow and earned a Doctorate in Medicine (MD). During this time, he developed an interest in utilising new surgical technologies and techniques in his practice in order to deliver the best care to his patients.

Now practising privately at BMI Goring Hall Hospital and the Spire Montefiore and Spire St Anthony's Hospitals, Mr Sains is a dedicated surgeon who is known for his expertise and excellence in patient care.

Mr Sains has a keen interest in patient safety, medical law and clinical governance. His current roles apart from being a consultant surgeon at the Royal Sussex County Hospital, Brighton are the governance lead for the department of surgery and is one of the Medical Examiners for the Trust. Also his interest in teaching and training of new surgeons and medical students holds the title of honorary clinical senior lecturer at Brighton and Sussex Medical School. 

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