Background: Constipation is a common digestive disorder in the elderly population, which has a considerable impact on various aspects of their lives. Traditional and complementary medicines are two common treatments for constipation. This study was aimed at comparing the effects of abdominal massage and oral administration of sweet almond oil on constipation and quality of life among elderly people.

Methods: In this single-blind study, 90 eligible elderly people were randomly selected according to ROME IV diagnostic criteria from October 2020 to May 2021 and were divided into three groups using block randomization (n = 30). In the oral consumption group, 126 ml sweet almond oil was administered during seven sessions held over two weeks (18 ml every other day). The abdominal massage group was provided with abdominal massage with the same amount of sweet almond oil during seven sessions in two weeks. Finally, the third group (i.e., the control group) received no interventions. Constipation was measured using the Constipation Assessment Scale (CAS) and the Bristol Stool Form Scale (BSFS) at baseline and on the 15(th) day of the intervention. Patient Assessment of Constipation-Quality of Life (PAC-QOL) was also applied before and after the intervention (day 15). The data were entered in to the SPSS 22 software and were analyzed using chi-square t-test, paired t-test, independent t-test, and ANOVA. p ≤ 0.05 was considered statistically significant.

Results: The results revealed a significant decrease in the CAS score in the oral consumption group (i.e., oral administration of sweet almond oil; from 7.81 ± 2.62 to 1.15 ± 1.08, p < 0.0003) compared to the abdominal massage group (i.e., abdominal massage; from 8 ± 2.57 to 2.26 ± 1.81, p < 0.0002) and the control group (from 7.73 ± 2.53 to 6 ± 2.74, p < 0.0002). Additionally, the stool consistency score in BSFS was significantly higher in the oral consumption group in comparison to the two other groups (p < 0.0003) before and after the intervention. Furthermore, the quality of life score decreased more significantly in the oral consumption group (from 75.04 ± 7.66 to 28.15 ± 3.30, p < 0.0003) than in the abdominal massage group (from 81.15 ± 5.15 to 43.26 ± 4.13, p < 0.0001) and the control group (from 79.62 ± 4.76 to 62.31 ± 6.40, p < 0.0008).

Conclusion: Since the oral administration of sweet almond oil and abdominal massage was highly influential in the participants' constipation scores and quality of life, these cost-effective methods with low complication rates are recommended to be used alongside other treatments in managing constipation among older adults.