The small intestine and irritable bowel syndrome (IBS): a batch process model

Area of Science:

• Gastroenterology and computational modeling.
• Investigates the physiological mechanisms underlying irritable bowel syndrome (IBS) through a systems biology approach.

Background:

• Irritable bowel syndrome (IBS) symptoms are modeled as arising from malfunctions in a three-section batch process of the small intestine.
• This model is regulated by a brain controller with four sub-controllers, each utilizing a specific neurotransmitter and managing transport or chemical additions.

Observation:

• Intestinal transport sub-controllers manage food movement, mixing, absorption, and transfer, with outputs dependent on sensor inputs.
• A default condition, normally active in the absence of food, causes forward movement at a speed influenced by fiber content when a transport sub-controller fails.

Findings:

• High-speed default transport, triggered by specific fibers, leads to IBS symptoms.
• Intestinal constriction to form a 'barrier' against fast flow causes constipation, cramping, and bloating.
• Diarrhea occurs when the final intestinal section exhibits fast default speed transport.

Implications:

• Sub-controller dysfunction due to neurotransmitter deficiency or sensor damage can manifest as diverse IBS symptoms.
• Understanding these model faults offers insights into the heterogeneous nature of IBS and potential therapeutic targets.
• This computational model provides a framework for exploring the complex interplay of neural, chemical, and mechanical factors in intestinal disorders.