Lipitor, also known as Atorvastatin, is a medication used to lower cholesterol levels in the body [1]. According to the National Health Service (NHS), the most common side effects of Lipitor are headache, aches and pains, and digestive problems such as constipation, diarrhea, and flatulence [2]. The Mayo Clinic also lists digestive problems as a potential side effect of Lipitor, including nausea, abdominal pain, and indigestion [3]. However, neither source mentions any specific effects related to taking Lipitor at night.

In general, it is recommended to take Lipitor at the same time each day, with or without food, as directed by a healthcare professional. It is also important to follow any other instructions provided by the healthcare professional, such as avoiding certain foods or beverages that may interact with the medication.

It is possible that taking Lipitor at night may affect digestion in some individuals, but there is no clear evidence to support this claim. If you experience any digestive problems while taking Lipitor, it is important to discuss this with your healthcare professional to determine the best course of action.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.nhs.uk/conditions/statins/side-effects/
[3] https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/side-effects/drg-20067003