possible causes of SIBO
Content
1. Impaired Flow through the Small Intestine
2. Causes for Impaired Flow
1. Impaired Flow through the Small Intestine
Obstructions or restrictions in the small intestine can be caused by structural or anatomical factors. Common causes include adhesions resulting from abdominal surgery, endometriosis, or dysfunction of the ileocecal valve, which may occur due to scarring in conditions such as Crohn’s disease.
1. Causes for Impaired Flow
Abdominal adhesions can contribute to the development of Small Intestinal Bacterial Overgrowth (SIBO) by disrupting normal intestinal motility. These scar-like structures, which often form after surgery, inflammation, or infections, can create mechanical blockages in the digestive tract. This slows the passage of food, leading to stagnation within the intestines. The prolonged transit time allows bacteria to overgrow in the small intestine by providing an extended supply of nutrients and disrupting the natural balance of gut flora. Additionally, adhesions can impair the function of the Migrating Motor Complex (MMC), which is responsible for cleansing the small intestine between meals. As a result, the risk of SIBO increases, potentially causing symptoms such as bloating, diarrhea, or constipation.
The endometrium refers to the lining of the uterus. In endometriosis, tissue similar to the endometrium grows outside the uterus in other parts of the body. While intestinal endometriosis primarily affects the large intestine, it can occasionally impact the small intestine as well (1). Endometriotic tissue can protrude into the intestine or grow on its surface, obstructing the normal flow of contents. Additionally, endometriosis is known to promote the formation of adhesions within the abdominal cavity, further contributing to restricted intestinal movement.
The ileocecal valve is located between the ileum (the last section of the small intestine) and the cecum (the first section of the large intestine). Its primary function is to prevent the backflow of contents from the colon into the small intestine. Unlike the small intestine, the large intestine contains a significantly higher concentration of bacteria. If the ileocecal valve becomes dysfunctional, bacteria from the colon can migrate into the small intestine, increasing the risk of SIBO.
Another potential anatomical cause of impaired intestinal flow is Ehlers-Danlos Syndrome, a connective tissue disorder. In this condition, connective tissue is overly elastic, affecting the structural support of the intestines. As a result, the intestines may be less securely positioned within the abdominal cavity, leading to unfavorable positioning and potential blockages.
References
- Townell NH, Vanderwalt JD. Intestinal endometriosis. Postgrad Med J. 1984 Aug;60(706):514-7. doi: 10.1136/pgmj.60.706.514. PMID: 6382223; PMCID: PMC2417966.
