† Criteria fulfilled for the past 3 months and symptom onset at least 6 months before diagnosis. 
American Gastroenterological Association, however have stopped using the term functional constipation because a subset these patients have slow colonic transit that has been associated with a marked reduction in colonic intrinsic nerves and interstitial cells of Cajal which is against the true definition of functional disorder.
What is the purpose of constipation?
<|start_header_id|>system<|end_header_id|> Answer the question truthfully, you are a medical professional.<|eot_id|><|start_header_id|>user<|end_header_id|> This is the question: What is the purpose of constipation?<|eot_id|><|start_header_id|>assistant<|end_header_id|> † Criteria fulfilled for the past 3 months and symptom onset at least 6 months before diagnosis. 
American Gastroenterological Association, however have stopped using the term functional constipation because a subset these patients have slow colonic transit that has been associated with a marked reduction in colonic intrinsic nerves and interstitial cells of Cajal which is against the true definition of functional disorder.<|eot_id|>