Several things can cause IBS symptoms to be worse in the morning, including your circadian rhythm, gastrocolic reflex, and stress.
It’s common for IBS symptoms to be worse in the morning. This is due to the way the large intestine functions. Stress can also play a role.
The symptoms can vary from day to day. They might even disappear for a few days, only to return again.
Circadian rhythm
Your circadian rhythm regulates your sleep-wake cycle and the motility of your large intestine.
According to a 2020 reviewTrusted Source, colonic motility decreases during sleep and increases when you wake up. This could trigger IBS symptoms in some people.
The review also found that a disrupted circadian rhythm is linked to IBS. Potential causes of impaired circadian rhythm include:
- jet lag
- shift work
- irregular sleep-wake rhythm
- delayed sleep phase disorder
- advanced sleep phase disorder
