A method, a data processing unit, and system thereof for monitoring excrement data of at least one absorbent article for seeking a pattern of excrement events for a monitoring period is disclosed. The at least one absorbent article being associated with a person wearing said at least one absorbent article. The method includes acquiring excrement data including data for at least two time periods, each substantially corresponding to the monitoring period for which a pattern of excrement events is sought; providing a series of sequential non-overlapping time intervals, together extending substantially over the monitoring period; and associating the time mark of each associated excrement event with a corresponding time interval. The excrement data includes information in form of excrement events into said associated absorbent article, and wherein each excrement event has an associated time mark or associated time information from which an associated time mark may be derived.