It was a non-randomized prospective study conducted in the Department of Obstetrics and Gynaecology in tertiary care hospital, Punjab, India, from 2014-2015. Hundred women with endometriosis stage I-IV were enrolled for the study. The inclusion criteria were, women requiring pain relief postsurgery and did not want to conceive for six months or more after surgery.

A detailed history including symptoms like infertility, chronic pelvic pain, dyspareunia were noted. A general physical and gynaecological examination was carried out before surgery. Patients were subjected to transvaginal sonography for size of endometriomas. All the patients were taken up for laparoscopic staging and cystectomy. After the surgery, patients were divided into two groups of 50 each. Group A was started on danazol 600 mg once daily. In Group B, LNG-IUS was inserted during immediate post operative period.

All patients were monitored with clinical and gynaecological examination. Relief of pain was assessed using a Visual Analogue Scale (VAS) on a scale of 1-10 after 3^rd and 6^th months of surgery. The adverse effects [6] of danazol and LNG-IUS were also noted. The number of patients willing to retain the device at the end of study was assessed as a response to treatment. Transvaginal sonography was done at the end of 3^rd and 6^th months of surgery to look for size of lesions more than 3 cm as possible evidence of recurrence. Four patients of Group A were non-compliant to treatment and four lost during follow up. Four patients of Group B had their LNG-IUS removed due to abnormal uterine bleeding.

Study protocol was approved by Ethical Committee of Institution. Informed and written consent was taken from all the patients.

Mean and standard deviation were computed. The results were analysed using percentages and Chi-square test. The level of significance was taken as 0.05. The data were statistically analysed by using SPSS 20.0.

The mean age of patients at presentation was 30.26±2.5 and 30.14±2.36 years respectively in each group. [Table/Fig-1] shows number of patients in each stage of endometriosis. Fifty percent patients were in stage IV. There was almost equal distribution of patient’s stage wise in both the groups. Eight and four patients from group A and B respectively were lost during follow up [Table/Fig-1]. Most patients presented with complaint of infertility and pelvic pain (49% and 43% respectively). Only 8% patients presented with other complaints like dysmenorrhoea, deep dyspareunia, dyschezia and dysuria.

Pain was assessed using the VAS score on a scale of 0 to 10. Pain relief was significantly more with increase in period of treatment in both the groups. In Group A- 23.8% patients got pain relief after three months of treatment and this increased to 38.0% after six months. In Group B- 32.6% patients reported pain relief after three months and 65.2% after six months. It was observed that LNG-IUS was significantly (p<0.05) more effective in relieving pain compared to danazol. It was further observed that more number of Stage IV patients showed pain relief compared to other stages in both the groups [Table/Fig-2].

The recurrence rate as measured on ultrasound after 3^rd and 6^th months of study is shown in [Table/Fig-3]. It can be seen that it is significantly lower in Group B compared to Group A.

The adverse effects observed with danazol were weight gain (20%) and acne (10%). Few patients (2-7%) complained bleeding and nausea as well. In LNG-IUS users, the only side effect noted was irregular uterine bleeding which decreased with time (65.2%, 50% and 43.47% patients after 1, 3 and 6 months of surgery respectively).

Sixty eight percent of patients were willing to retain LNG-IUS at the end of six months.

Endometriosis is a chronic gynaecological disorder of ectopic endometrium. Mean age at presentation in our patients was 30.2±2.4 years. Similar age of presentations has been reported by other workers. Preciado Ruiz R et al., reported an incidence of 35% with an average age at presentation of 30 years [7]. In our study 50% patients presented in stage IV directly because signs and symptoms of endometriosis are non-specific and the diagnosis becomes difficult. The gold standard of diagnosis remains to be laparoscopy [8].

In our study 43% of patients presented with the complaints of chronic pelvic pain. This symptom is characteristic of advanced stage endometriosis (stage III and IV). The severity of pain in endometriotic lesions is related to the recurrent, cyclic, micro bleeding in the implants [9]. This explains the chronic pelvic pain in severe lesions. Similar complains of pain and infertility in endometriosis patients have been reported by other studies as well [10].

The treatment options for endometriosis include- ovarian suppression therapy, surgical or a combination of both the strategies. Through surgery visible areas of endometriosis are removed and the anatomy is restored by division of adhesions. Medical therapy aims to inhibit the growth of endometrial implants by suppression of ovarian hormones [11]. Due to its high recurrence rate, both surgical and medical management is required. Significant pain relief was observed in patients using LNG IUS as compared to danazol users. The release of LNG appears to have a direct effect on endometrial deposits through peritoneal fluids possibly by a haematogenous spread. LNG decreases blood flow in uterine artery and spiral arterioles causing reduction in dysmenorrhoea and reduction of recurrence [12]. Danazol has been shown to be more effective in stage I or II [13]. It acts by producing high levels of androgen and low levels of oestrogen in the body. This hormonal environment stops menstruation and suppresses the growth of endometrial implants, causing them to degenerate. The effect of danazol was not significant in stage III and IV.

Recurrence of endometriosis after conservative surgery is not infrequent [14]. Recurrence of pain decreases with LNG-IUS for symptomatic endometriosis [11]. The use of LNG-IUS is an effective alternative for the medical treatment of women having recurrence of endometriosis and chronic pelvic pain [11]. In the present study recurrence rate was not appreciable with LNG-IUS but 19.0% and 7.1% recurrence was noted in danazol users at 3^rd and 6^th months [15]. Recurrence rate was significantly lower at 6^th month compared to 3^rd month in both the groups and further recurrence was significantly lower in Group B compared to Group A. These patients with recurrence of pain were managed effectively with NSAID.

Of the adverse effects, irregular bleeding was reported with LNG-IUS. This has been documented earlier as well. The common adverse effects with danazol were weight gain and acne. Few patients complained bleeding and nausea as well. Many of the side effects are due to its androgenic action [16].

In Group B majority (68%) of patients were willing to continue with LNG-IUS at the end of the study. Patient satisfaction itself shows the efficacy of the drug. This percentage was comparable to the study by Lockhat FB et al. [17].

It was a small study with limited participants. Larger trials are required to comment on the effectiveness of LNG-IUS and danazol for the relief of postoperative pain in endometriosis.

Postoperative pain in endometriosis is very distressing. Various methods to decrease the postoperative pain in endometriosis include danazol and LNG-IUS. LNG-IUS is found to be an effective method in our study. Larger studies are required to conclude the same.