As we previously discussed, a diagnosis of IBS can often be quite unhelpful from a practical standpoint. It does not identify a cause for symptoms and often there are minimal treatment interventions available.
At this point it is useful to understand the diagnostic criteria for IBS:
A patient might have IBS if they had recurrent abdominal pain on average at least one day/week in the last three months, associated with two or more of the following criteria:
related to defecation
associated with a change in frequency of stool
associated with a change in form (appearance) of stool
*Criteria fulfilled for the last three months with symptom onset at least six months prior to diagnosis
- Rome IV criteria for IBS
As you can see, symptoms of nausea, abdominal discomfort (less severe than pain), bloating or distension, excessive flatulence or belching, heartburn/GERD are left out.
There are some clinical signs and symptoms that make SIBO a more likely diagnosis.
Aspects of the patient story may include:
Symptom onset following food poisoning.
Symptom worsening with higher fibre or sugar diet. Specific trigger foods may include: apples, garlic/onions, grains, asparagus, avocado, watermelon, lentils, cauliflower, apricots, plums, beans, cabbage, among others.
Low appetite or sensation of heaviness after eating.
There are also several conditions associated with SIBO. An incomplete list includes:
Restless legs syndrome
Iron and/or B12 deficiency
Gallbladder removal or steatorrhea (fatty stool)
Identifying and understanding the root cause of IBS (and other digestive symptoms), helps to implement targeted treatments and strategies.
But SIBO itself has an underlying cause. Or, rather, a few potential underlying causes.
History of acute bacterial gastroenteritis (most common cause)
Hypochlorhydria (low stomach acid)
Bile insufficiency and Bile-deconjugation
Traumatic Brain Injury (TBI)
Intestinal strictures or adhesions
Ileocecal valve dysfunction
When symptoms of IBS are overlaid with a history of any of these things the investigation of SIBO is even more warranted.
On a closing note, Stress is still commonly discussed as a main cause or contributor to IBS. And while stress will often exacerbate symptoms if does not appear to the main cause.
A series of studies involving military personnel found that there were no significant correlations between stress factors and IBS. There was, however, a significant correlation between developing chronic GI disorders and a history of acute bacterial gastroenteritis.
This is not to suggest that stress reduction/management techniques will not benefit digestive symptoms. On the contrary, the digestive tract is sensitive to the effects of stress – from both a physiological and neurochemical standpoint. In the next entry we will discuss some of these interactions and implications.
(Riddle MS, et al. Am J Gastroenterol. 2016)
(Porter CK, et al. Gastroenterology 2013)