Women eligible for the study are adult, non-(post)menopausal individuals who have received a laparoscopic and histopathological diagnosis of en-dometriosis. They have been experiencing cyclic pain (before, during, and/or after menstruation or monthly flare-ups without menstruation) for at least two months. Participants do not expect to undergo gynecologic or other surgical procedures for en-dometriosis during the study period and are not pregnant or breastfeeding. They must have no external factors interfering with their sleep for three or more nights per week, such as work, noise, or caregiving responsibilities.

intervention: 6 item diary twice a day over the course of 2 months.

Women eligible for the study are adult, non-(post)menopausal individuals who have received a laparoscopic and histopathological diagnosis of en-dometriosis. They have been experiencing non-cyclic pain for at least six months. Participants do not expect to undergo gynecologic or other surgical procedures for en-dometriosis during the study period and are not pregnant or breastfeeding. They must have no external factors interfering with their sleep for three or more nights per week, such as work, noise, or caregiving responsibilities.

intervention: 6 item diary twice a day over the course of 2 months.

6-item diary, twice a day, over the course of 2 months.

Morning assessment: Irrespective of how much you slept, how good was the quality of your sleep? (0= not at all, 7= very good).

Evening assessment: How much pain did you experience today? (0= none, 7= very much)

Evening assessment:

How good was your mood overall today? (0= No good mood at all, 7= very good)

Evening assessment:

How much stress did you experience today? (0= none, 7= very much)

Evening assessment: Have you menstruated today or experienced menstrual-like symptoms (e.g., spotting/intermittent bleeding,...)?

• Yes
• No
• Not applicable