In short, the main difference between IBS and IBD hides in the nature of those conditions. While IBS is a syndrome (a combination of various symptoms) that does not trigger colon abnormalities, IBD is classified as a disease, causing an immune response and imposing risk of intestine damage at genetically predisposed patients. IBD is chronic persistent inflammatory diseases with huge impact of the quality of life of the patients 
At first glance, you may see very little differences between symptoms of Irritable bowel syndrome (IBS) and Inflammatory bowel disease (IBD). But even though those two health conditions both affect the digestive tract and may have some similar symptoms, they are very different from each other when it comes to factors like health risks, causes, and most importantly – treatment.
This article will show the main differences between IBS and IBD and will help you to recognize and understand those two health conditions.
However, this article does not aim to provide information for self-diagnosis or substitute medical consultation. Consulting a gastroenterologist or your healthcare provider is essential if you experience any gastrointestinal disorder symptoms.
Now let’s get started.
What is the difference between IBS and IBD symptoms?
Common IBS symptoms include  :
- Abdominal pain
- Urge for bowel movement
The same symptoms can also can be found or indicate signs of IBD. However, as Crohn’s disease can affect every part of the digestive tract, from mouth to anus, the symptoms can vary depending on the affected area. Ulcerative colitis (which is the second type of IBD is affecting the colon, starting from the anus). Besides, as the term IBD includes several diseases (Crohn’s disease; ulcerative colitis; indeterminate colitis), the symptoms between those may also differ.
Yet, the most common symptoms that IBD patients may experience include :
- Rectal bleeding/Bloody stool (Ulcerative colitis)
- Weight loss
- Reduced appetite
- Excessive anxiety
Keep in mind that the symptoms may vary across individuals, and patients can easily confuse IBS and IBD. For example, an IBD patient may consider his/her symptoms for IBS, and as a result, lack proper treatment. For that reason, being diagnosed by a professional is essential.
What are the possible IBS and IBD complications?
According to an overview of IBS in the Institute for Quality and Efficiency in Health Care, IBS is not a dangerous health condition and is unlikely to be life-threatening. However, some patients might experience very severe symptoms that compromise their quality of life and lead to anxiety and even depression. 
In comparison, the lack of appropriate treatment of IBD can lead to more severe health issues or death.
Untreated ulcerative colitis may weaken the intestinal wall and perforate it, as well as cause rapid dilation of the colon (toxic megacolon).
Complications in Crohn’s disease may include:
- Fistula (abnormal “tunnel” connecting the intestine to the skin or another organ)
- Stricture (intestinal blockage due to scarring)
- Abscess (collection of pus)
- Perforated bowel (causing whole in the intestine)
- Malabsorption of nutrients
What is more, IBD can also significantly increase the risk of colon cancer formation, as well as blood clots formation (three items higher risk than in individuals without IBD). 
The most useful examination is colonoscopy with intubation of the terminal ileum (Crohn's usually starts from the small intestine). After the colonoscopy, the gastroenterologist can say for sure is it IBD or IBS.
Causes of IBS and IBD
The exact causes for both IBS and IBD are still unknown to medical researchers. However, some assumptions exist.
According to Crohn’s & Colitis Foundation, IBS may be triggered by sensitivity to gas and bloating, changes in gastrointestinal microflora, and other body chemicals and compounds (like hormones). Besides, some patients may experience more severe IBS symptoms after having large meals or experiencing strong stress, as well as after suffering from colon inflammations and infections. 
The same source suggests that the following combination of factors may cause IBD:
- Genetic predisposition (when a close relative also has IBD)
- Environmental factors which can cause defensive immune response like bacteria and viruses.
- Change in gut microbiota balance
- Immune system overreaction (which doesn’t wind down over time) or disturbance
IBS and IBD risk factors
According to Harvard Health Publishing, IBS usually starts at early adulthood and affects twice more women than men. The source suggested that stress is unlikely to play a role in IBS development, but may increase the severity of the symptoms, together with consumption of specific foods (usually ones that ferment in the colon), and smoking. 
Besides, some health conditions may also increase the risk of IBS development.
For example, a 2017 study in the Journal of Gastroenterology concluded that patients with infectious enteritis bear 4 times greater risk of later IBS development, compared with healthy individuals. The study also suggested that women may be more predisposed to the syndrome than men, as well as people suffering from high levels of psychological stress and who took antibiotics during enteritis. 
Patients are usually diagnosed with IBD between the age of 15 and 35, and the disease affects men and women equally. The risk factors for IBD are directly related to the potential causes for this condition. A 2019 study published in the Journal of Gastroenterology identified 6 factors that may increase the risk of IBD development :
- Urban living
- Antibiotic intake
- Use of oral contraceptives
- Consumption of soft drinks
- Vitamin D deficiency
- Non–Helicobacter pylori–like enterohepatic Helicobacter species (potentially pathogenic microorganisms that colonize the mucus)
Additional risk factors which can intensify IBD symptoms include  :
- Intake of nonsteroidal anti-inflammatory drugs (e.g., aspirin and ibuprofen)
- Consumption of pro-inflammatory foods (e.g., fried, sugary, high fiber foods)
Treatment of IBS and IBD
Both IBS and IBD are chronic conditions and cannot be treated for short period of time. However, treatment therapies prescribed by specialists may include both activities and medications to control the symptoms and reduce their severity.
IBS treatment can include the intake of medications to relieve diarrhea, constipation, bloating, and abdominal pain. Also, patients are often advised to follow specific eating plans, like FODMAP or lactose-free diet, as well as to control their portions and pay attention to what foods cause symptom worsening. 
IBD treatment therapies depend strongly on the severity of the disease and the affected organs. They may include eating regimes, anti-inflammatory medications, antibiotics, or biological treatment with selective new class anti-inflammatory treatment. Additional treatment may require surgery. Therefore, patients with IBD should strongly follow the advice of their healthcare provider in order to manage their condition and control its progression and complications.