Wollongong Private Hospital
Part of Ramsay Health Care

Thomas Lee

A change in bowel habits – when do I worry?

Nov 21, 2019

There is an expectation that our bowel should have a particular pattern of behaviour and it should continue to do so for the rest of our lives…. But we know nothing in life is like that!

Our bowel is a dynamic system that responds to external influences such as our diet and emotional state. Other factors are the interaction between our gut microbiome and host immune system and sometimes, a manifestation of an underlying immune dysregulation such as inflammatory bowel disease or coeliac disease.

The interaction between our mind and gut (gut brain axis) forms the basis of many patient’s gut symptoms such as abdominal bloating, pain or discomfort and alternating bowel habits. These symptoms often coincide with major life events such as job interviews or exams, relationship or financial issues and can date back to school days! It forms the foundation of irritable bowel syndrome (IBS) in many. We all have stresses in life that can be manifested through our gut and are often self-resolving as the stressful event passes. People with underlying mental health challenges such as anxiety, depression, PTSD and OCD have a more difficult time. This cohort have an intrinsic visceral hypersensitivity where response to normal physiological luminal distension and peristalsis are often interpreted as discomfort or pain. The cycle self-perpetuates through catastrophising of the symptoms with ‘do I have cancer? Am I going to have a colostomy bag?’ With a third of General Practice workload being mental health related, we are seeing a lot more IBS. It is important to note that although IBS is common, it is still a diagnosis of exclusion, that is, we need to make sure there is no other pathology first.

The main differential diagnosis is inflammatory bowel disease (IBD) and it is often confused with IBS. IBD is an immune disorder where continuous ulcerations are often found on the lining of the colon (ulcerative colitis) or patchy superficial and/or deep ulcerations are noted from mouth to anus +/- fistula formation in some situations (Crohn’s disease). Symptoms include a change in bowel habits, blood per rectum, weight loss and nocturnal abdominal pain and/or bowel action. As the underlining pathology is immune mediated, medical therapy involving immunosuppression is an effective way to manage the disease.

IBD is a heterogenous disease therefore the management needs to be tailored individually. Timely usage of immunosuppression and escalation to biological therapy can prevent surgery in the majority of patients. Access to IBD clinical trials also allow patients to trial the latest medication long before it is PBS listed and be at the forefront of medical care. We also need to recognise any medication related side effects early on and know how to prevent it. The role of faecal microbiota transplantation (FMT) remains a research tool at present.

As highlighted in the table, there is a need is to exclude bowel malignancy especially in the presence of iron deficiency, with or without anaemia, rectal bleeding and unintentional weight loss. First degree family history of bowel cancer diagnosed before the age of 50 is significant.

If still uncertain of the significance in a change of bowel habits – especially in the setting of loose bowel motions then first exclude an infectious cause with stool M/C/S and O/C/P. Faecal calprotectin test is a quick and easy way to differentiate between an inflammatory cause such as IBD and a non-inflammatory cause such as IBS. It quantifies calprotectin proteins (by product of the neutrophils degranulation) in the stools. In the setting of mucosal inflammation, neutrophils are leaked out into the stools and release calprotectin proteins. The higher the reading, the more severe the mucosal ulceration is likely to be.

Finally, listen to your gut. The sixth sense of a physician is also very accurate!

Rome IV Criteria

A/Prof Thomas Lee

P: 02 4210 7870
F: 02 4227 1502