You might wish to see a report of correlated absences. This will show you two students that have been given an absent mark on the same day or that were given the same absent mark for the same amount of days.
To get to the page click > Students > Attendance > Absentees > Correlated/ Siblings.
You can change the start and end dates using the filter section at the top.
Using the tick boxes and clicking on the blue pencil will give you a selection of follow up options. For example, sending an SMS to the selected students' Primary Guardians or creating an intervention.
For more information, you can watch a video about this topic here.