Gastrointestinal Motility Disorders

GI motility disorders result from damage to gut muscles or nerves that disrupts food transit through the digestive tract. Damage can be congenital or develop from conditions like diabetes or medication side effects. Nerve or muscle dysfunction prevents normal coordinated contractions, leading to various symptoms depending on which GI segment is affected.

Achalasia occurs when the lower esophageal sphincter fails to relax properly, preventing food from passing into the stomach. This causes difficulty swallowing and food regurgitation. The sphincter's inability to open disrupts normal esophageal motility, trapping food in the esophagus and causing discomfort.

GERD involves retrograde flow of stomach acid into the esophagus, causing heartburn and discomfort. Functional dyspepsia affects the upper digestive tract, causing epigastric pain, early satiety, and postprandial fullness. While GERD involves acid reflux, functional dyspepsia is a functional disorder without necessarily involving acid reflux.

Gastroparesis slows abdominal muscle movement, preventing the stomach from contracting effectively to push food into the small intestine. This delayed gastric emptying causes nausea, vomiting, pain, and bloating. The muscular dysfunction disrupts the normal coordinated contractions needed for food transit.

Constipation results from impaired colonic motility, causing infrequent bowel movements and difficulty passing stool. IBS, a functional GI condition, leads to altered bowel habits and abdominal pain, causing either diarrhea or constipation. Constipation is a symptom of impaired muscle function, while IBS involves motor abnormalities with variable bowel patterns.

Medications targeting GI motility address underlying muscle or nerve dysfunction. Drugs affecting tract motility include various classes that either enhance or reduce GI contractions depending on the disorder. Treatment selection depends on whether the condition requires increased motility, decreased motility, or symptom management.

Nerve or muscle damage disrupts the coordinated contractions needed for food transit, but symptoms vary by location and severity. Esophageal damage causes swallowing difficulties, gastric damage causes delayed emptying, and colonic damage causes constipation. The specific GI segment affected determines whether symptoms involve reflux, delayed transit, or altered bowel movements.