James is a 52-year-old man who visits his primary care physician with complaints of chronicconstipation, experiencing infrequent bowel movements, straining during defecation, and asensation of incomplete evacuation. He reports that his symptoms have been worsening over thepast year. His diet is low in fiber, and he leads a sedentary lifestyle due to his desk job. Aphysical examination and digital rectal exam reveal no obvious abnormalities.To further understand the underlying issue with James' bowel movements, his doctor orders acolonoscopy, which shows no structural abnormalities, and a balloon expulsion test, whichindicates difficulty expelling the balloon. James is diagnosed with functional constipation.
Questions:
(a) Based on the scenario, what factors might be contributing to James' chronicconstipation?
(b) Describe the normal physiology of defecation, including the roles of the rectum, analsphincters, and nervous system in this process.
(c) Explain the possible pathophysiological mechanisms that could lead to chronicconstipation in James' case.
(d) What are the potential complications of untreated chronic constipation?
(e) What treatment options and lifestyle modifications can help James manage his chronicconstipation effectively?