Partially hydrolyzed guar gum (PHGG) is a vegetal, water soluble, non-viscous, non-gelling dietary fiber that is derived from guar gum, a water-soluble, viscous, gelling polysaccharide found in the seeds of Cyamopsis tetragonolobus. PHGG is food for special medical purpose and available over-the-counter. It is as effective as lactulose treatment in relieving constipation associated abdominal pain in children. Up-to-date, there is no randomized study regarding the effectiveness of PHGG in reducing constipation in long term care facility residents, the investigator therefore would like to perform a prospective, randomized study to assess its effectiveness in long term care facility residents to improve fecal characteristics and its effect on use of laxative agents.

This is a prospective, randomized, single blinded, parallel-group trial for the residents in long term care facilities covered by Community Geriatric Assessment Team of Queen Mary Hospital and Fung Yiu King Hospital. The investigator aim to recruit 52 subjects from those long term care facilities.

Subject fulfilling the inclusion criteria will be screened from the Community Geriatric Assessment Team (CGAT) of Fung Yiu King Hospital by the investigators. Study information will be explained to subject in detail and consent form (in Chinese) will be given to subject. Before commencing, subjects will be allowed to have one week to consider joining the study.

After informed consent, subjects will be randomly assigned into 2 groups. One group receive PHGG following study protocol (treatment group). Another group will be control group, no PHGG will be given. For treatment group, subjects will take 5g PHGG per day (which equals 4.2g dietary fiber) through mixing with 20ml water during treatment period. Since after mixing with PHGG, the water remains colorless and odorless, control group will also be given 20ml water by long term care facility staff as a blinding process to participant.

The study consist of two periods: a 2-week run-in period and a 4-week treatment period. During run-in period, patient's demographic characteristics will be recorded. Eligibility of patients to proceed to the treatment period will be determined, according to their baseline symptoms stool log. Stool frequency, stool characteristics (according to Bristol stool scale ranging from 1: hard stool to 7: liquid stool) and use of laxative medication will be recorded through a record diary given to subjects. During treatment period, both group of subjects need to record stool frequency, stool characteristics and use of laxative medication. Any adverse reaction will be recorded. Satisfaction of subjects towards PHGG will be assessed by questionnaire with quantification through Likert scale. Subjects will be instructed to maintain their usual daily activities including exercise, food habits, and medication consumption.

Outcome measures:

Primary outcome Fecal frequency (assessed by recording defecation times/day) Fecal characteristics (assessed by Bristol Stool Scale)

Secondary outcome Use of laxative agents per day

Inclusion Criteria:

• Long term care facility residents at the age of 65 or above.
• All participants give written informed consent.
• Participants must be available to complete the study and comply with study procedures

Exclusion Criteria:

• Previous major surgery of the abdomen
• Use of PHGG in the 4 months prior to the study initiation
• Chronic constipation due to primary organic disorder of the large bowel e.g. neoplasia, post-radiation or inflammatory strictures
• On regular laxative treatment
• Patient with severe hypothyroidism
• Patients suffering from disease of the spine cord
• Subject receiving antibiotics within 3 month